FAQ: Troubles, bugs, and errors in SuperMemo 15

If you believe you have found a bug not mentioned here please report.

See also: 

Some bugs and error messages reported in earlier SuperMemos are believed to have been removed from SuperMemo 15, and are not listed here. However, it is still possible some errors reoccur in SuperMemo 15. For that reason see also:


In case of persistent errors, use File : Repair collection
(Allen Hall, Fri, Aug 31, 2001 22:37)
Question:
SuperMemo has just displayed the following error: "Fatal error! Cannot open registry files Registry=C:\program files\systems\ALLTOPO SHORTCUTS\registry\category. File not found". I need this collection. Do you know of a fix?
Answer:
In case of collection errors (esp. those listed as fatal), you should do two things: 

  1. backup the collection (e.g. with File : Copy collection
  2. run a checkup procedure with File : Repair collection 

If you suspect a bug, write to us


If SuperMemo loses its vital files, you may need to restore the whole collection from a backup
(Juarez Barreto, Brazil, Friday, August 30, 2002 3:35 AM)
Question:
SuperMemo displayed the following error: 
  "Collection files missing! 
  Folder=C:\MEUS\ 
  Try to restore files that you have moved or deleted"
Answer:
On opening a collection, SuperMemo checks if its vital files are in place. If any of these is missing, the above error will show. Vital files are those that make recovering the collection impossible. For example, the text.rtx file contains the text of your elements. If this file is missing, SuperMemo will not be able to recreate the texts used in your collection. This will render it useless. Most likely reasons for the above error: 

  1. you moved the kno file without moving the associated folder. For example, if your collection is Meus then it is made of the file Meus.kno and folder [Meus]. If you move Meus.kno to the root of your c: drive and then try to open Meus.kno, SuperMemo will protest the absence of the [Meus] folder by displaying the message above
  2. you deleted, moved or renamed the folder associated with your collection (e.g. c:\meus associated with c:\meus.kno
  3. due to a virus, software or hardware malfunction, one the the vital files was deleted or its size was set to zero If you are unable to restore the deleted folder or files, you will need to resort to your most recent backup of the collection

Important: If you are not fluent with files and folders, it is safer to copy or move SuperMemo collections with tools available on the File menu (for example, File : Copy collection). Otherwise, it is very easy to pick the kno file in Windows Explorer and separate it from the rest of the collection. The error message as above will result. Recommended reading: Backup 


(Tomasz Szkopek, Nov 8, 1999)
Question:
I upgraded Advanced English 97 to SuperMemo 2000 and received the following error: Collection files access error ! Wrong A-Factor distribution. Is it dangerous?

Answer:
No. This is a harmless warning.
After upgrading all collections to SuperMemo 2000, you will always need to run File : Repair collection with Basic recovery checked. This is needed to calculate new values of A-Factors as the interpretation of A-Factors has changed slightly from SuperMemo 98 to SuperMemo 99


Question:
What is the reason of the message "Cannot open collection"?
Answer:
Most likely the collection is already opened by another user or another instance of SuperMemo


(Janusz Murakowski, Sun, Apr 29, 2001 7:55)
Question:
I am using Equation Editor via OLE. I received the following error: EQNEDT32 caused an invalid page fault in module EQNEDT32.EXE at 0167:00426365
Answer:
Errors in OLE components are often entirely independent of SuperMemo. Some applications are not stable enough for use with SuperMemo. Others need special workarounds


"Fatal error" may indicate a serious file damage in your collection
(rocky eversman, Sunday, July 08, 2001 7:35 PM)
Question:
I get the following error message: Fatal error! Cannot read data for element #17498, Choose abort to halt SuperMemo
Answer:
This message indicates that SuperMemo cannot access element information of the 17498th element. You should immediately backup your learning material and run File : Repair collection. At worst, you collection could have suffered a serious file damage to elinfo.dat file, which stores element data. This may require reverting to your latest backup. If file damage results in lost information, SuperMemo may not be able to restore collection integrity


You cannot open SuperMemo read-only collections
(Chuck Albritton, Mon, Aug 13, 2001 13:51)
Question:
I tried to open the file below from the MegaMix CD-ROM. 
SuperMemo has just displayed the following error: 
"Fatal error! 
Cannot create registry: 
F:\English\Languages\Basic Spanish (AudioVisual)\registry\comment. 
File access denied
"
Answer:
You cannot open collections whose files are marked read-only (as opposed to collections opened in SuperMemo's read-only mode). You need to install them on your hard disk first (e.g. with MegaMix Setup or manually by copying)


Some errors in SuperMemo are generated by Windows and can be ignored
(Steve Brown, Wed, Aug 15, 2001 1:03 PM)
Question:
I added a number of cards/elements. Upon exiting, I am getting the following message: " Access violation at address 0055F55B in module 'SM2000.EXE." Read of address FFFFFFFF"
Answer:
This message is most likely generated by Windows and in majority of cases should be harmless. Similar messages with varying addresses (e.g. 004034B4) are most likely in Windows ME or Windows 95/98 due to their instability. As a precaution though, it is recommended that you run File : Repair collection on your learning material at least once if you see this message again. In case it persists, please write to us


Burden=0 in a collection with memorized items indicates a serious problem
(Reto Schmid, Monday, August 27, 2001 1:55 PM)
Question:
SuperMemo has just displayed the following error: "Fatal error! Burden is zero in a collection with 87 memorized elements!"
Answer:
This error is an indication of a major problem in your collection. Burden=0 in a collection with memorized items could be caused by two major reasons: 

  1. You manually copied .kno file of one collection onto the same file belonging to another collection 
  2. Your computer crashed and the memory image of the .kno file has been overwritten (e.g. with zeros). This image was then saved back to the file rendering your collection unworkable 

You need to immediately execute File : Repair collection. If the problem is limited to .kno file, chances are SuperMemo will be able to recover lost information. However, if Repair collection fails, you may need to restore your most recent backup


Some errors may be very hard to reproduce and eliminate
(Reto Schmid, Monday, September 10, 2001 3:37 PM)
Question:
SuperMemo has just displayed the following error: "ElementNo=0 at CommitElement"
Answer:
Unfortunately, this is a kind of error that upon the analysis of the source code looks like it should never have happened. It occurs when the program requests that the element whose number is zero become memorized (naturally, no such element exists). However, before calling the CommitElement procedure, multiple tests are made to ensure that the element number is valid and existent. This analysis indicates that this error should never have happened assuming stable Windows environment, integral SuperMemo code and its image in memory, and assuming that no bugs at the compiler level (Object Pascal in this case). Without more data and the context, it seems impossible at this moment to confirm the existence of a bug in SuperMemo. This error might be related to: Burden=0 in a collection with memorized items indicates a serious problem


Remember to make a backup!
(Marcin Piekarniak, Poland, Dec 2, 1997)
Question:
How can I easily back up Advanced English 97? In Advanced English 94 the entire system could be compressed to a 1.4 MB file!
Answer:
It is possible to back up the learning process without backing up the contents of Advanced English (the contents is backed up on your original Advanced English CD-ROM). This way only the data pertaining to items in the learning process will be stored (not items themselves). Use File : Export : Learning process to export the data. Later, upon reinstalling Advanced English 97, you can restore the learning process with File : Import : Learning process : Text file


Your collection can suddenly appear empty!
(Michael Duggan, Canada, Nov 2, 1998)
Question:
I was cleaning up my hard drive and attempted to move SuperMemo from one folder to another folder. In the process I lost the data for a number of collections. Can I retrieve these data files and place them back in my collection? How do I do that?
Answer:
It is always recommended to move collections with File : Copy collection in SuperMemo. Otherwise, a frequent mistake is to copy the kno file without the folder that contains the actual collection files (see: Files used by SuperMemo).
Some customers also fall victim of the following scenario:

  1. user moves the whole SuperMemo folder to a new location using Windows tools
  2. user starts sm15.exe from the new location
  3. SuperMemo inspects supermemo.ini for the location of most recently used files and looks for them in the old location
  4. SuperMemo displays Cannot find <collection name> at <old location>. Create new files?
  5. User responds with Yes
  6. SuperMemo creates empty files with the old name
  7. User is convinced he lost his data while intact collections are safely stored at the new location

The simplest remedy is to answer No in Step 5 and open collections at the new location with File : Open collection


You can restore an empty backup
(Przemek S, Poland, June 8, 2000)
Question:

I used to regularly back up my Advanced English on a second hard disk. Today I tried to restore my backup and ... it looks as it is empty! Only one element inside! Help!!!
Answer:

There is a frequent mistake users make. To backup a collection, you need to copy both the kno file and the associated folder (e.g. file ae.kno and the folder [ae])(see: Collection files). Some inexperienced users copy only the kno file which is just 20KB of data! If you try to open an orphaned kno file, SuperMemo will reconstruct an empty folder structure.

To avoid this problem: Always back up collections with File : Copy collection or File : Tools : Quick backup. Do not use external tools unless you understand Windows, files, folders and SuperMemo very well!

To resolve the problem: it is possible the original folder associated with the kno file still exists on the hard disk! You can search for some files characteristic for SuperMemo (e.g. burden.dat or sm8opt.dat). Make an inventory of all kno files (search for *.kno) and all SuperMemo collection folders (search for burden.dat) on your hard disk. Once the inventory is made, try to carefully match up knos and folders and copy kno files to match the folders. Chances are that File : Open collection on one of these files will restore the lost backup. Note that you can easily find empty collections by checking the size of burden.dat. This file contains repetitions and is zero-sized on collections with no learning process


Use Copy or Move instead of File : Save as
Question:

Why isn't there Save As on the File menu?
Answer:
Because File : Copy collection does exactly what you would expect of Save As. The different name indicates, however, that the collection is not stored in memory but is updated on the hard disk on-the-fly. Therefore, instead of saving it under a new name, you just have to copy it to the new location. Collections are kept on the disk due to their often huge size (for example Advanced English is 700 MB large; of which the primary storage takes nearly 50 MB)


You can backup learning in large collections
(Michal Grodzki, Poland, Aug 20, 1998)
Question:
You advice the users of Advanced English 97 to make back-up copies with File : Export : Learning process. However, this does not back up the material introduced by the user. What is the best solution in a case when I want to add lots of my own items to Advanced English?
Answer:
You might try one of the following:

  1. Keep your own material in a separate collection. You can back up such a collection by compressing the <collection name>.kno file and the <collection name> folder into a single archive (e.g. with WinZip)
  2. If you prefer to add your items to Advanced English (e.g. in order to be able to search all material in one go), you might back up the contents of a single branch by transferring it into an empty system with Export : Transfer elements on the contents pop-up menu or by exporting it as text with Export : Source code (also on the contents menu). You can later restore your back-up after reinstalling Advanced English with Export : Transfer elements in the opposite direction or with File : Import : Source code in the latter case

There is a chance you can recover from a virus attack!
Question:
My computer was hit by a virus and SuperMemo reports integrity problems. What shall I do?
Answer:
Try File : Repair collection. If this does not help, you will need to use your latest working backup


If SuperMemo is unstable ... check your computer first
Question:

What should I do if SuperMemo displays strange error messages, aborts frequently, and File : Repair collection does not work?
Answer:
Make sure that your Windows is stable and you have no hardware problems. If the messages are displayed by Windows rather than SuperMemo itself (e.g. modules such as Kernel, User, Ctl3D, etc.), the problem is probably not with SuperMemo. Some hardware problems are a frequent reason for such situations, esp. if similar events happen with other applications. Check your memory, hard disk, system setup and the mainboard in the first order.
In case you are sure File : Repair collection is unable to recover your collection for reasons related to SuperMemo, write to SuperMemoMail


You may have problems displaying MS Equation formulas via OLE
(Tomasz Szynalski, Poland, Dec 2, 1998)
Question:
When I create an MS Equation formula in the OLE component, the equation is unnaturally large and distorted. How can I go around this bug?
Answer:
Rendering of the OLE object is done by the server application, MS Equation in this case. You have to fix the problem in MS Equation by adjusting display attributes (e.g. reducing the size of fonts in this case)


System error. Invalid window handle
(Bela Fodrovics, June 7, 2003)
Question:
SuperMemo displayed the following error:
"Cannot restore window coordinates
System error, code 1400. 
Invalid window handle

It appeared automatically after I connected and disconnected from the net.
Answer:
This error occurred outside SuperMemo while SuperMemo tried to rearrange the layout of its windows. It is indicative of a system-wide problem that should be temporary (e.g. resulting from a crash of one or more applications or services). Invalid window handle error is raised by Windows if operations on a non-existing or invalid window are attempted. If you restart Windows and SuperMemo, this error should not reoccur. If it does, you may need help from a software expert to test your Windows installation


SuperMemo can be getting slower!
(Pawel Galecki, Poland, Feb 10, 1998)
Question:
I have created my own collection that contains 700 items in the root. The system loads for nearly 60 seconds each time I open it! How can I speed this up?
Answer:
For performance reasons, you should limit the number of elements per branch to 50-100. For this purpose, set a lower value at Tools : Options : SuperMemo : Children limit per branch. To break up your 700-item category, run Tools : Arrange in folders on the contents window pop-up menu


Wrong A-Factor distribution error is harmless (#7561)
(Joanna Sierpowska, Finland, Fri, Nov 02, 2001 8:31)
Question:
SuperMemo has just displayed the following error: "Wrong A-Factor distribution"
Answer:
This error is usually harmless. It indicates that SuperMemo keeps a wrong A-Factor statistic. This statistic is only for your information, and does not affect the learning process. However, this error should not normally occur and may indicate a more serious underlying cause (e.g. file error, erroneous backup, etc.). Running basic File : Repair collection will correct this statistic.

This error can also occur after an upgrade to SuperMemo 2002. After upgrading all collections to SuperMemo 2002, you will always need to run File : Repair collection with Basic recovery checked. This is needed to calculate new values of A-Factors as the interpretation of A-Factors has changed slightly from SuperMemo 98 to SuperMemo 99


Errors in repetition history
(Beta, Slovakia, Apr 03, 2002)
Question:
Why do I get this error at Repair collection: "Updating erroneous repetition history"
Answer:
Most likely you have played with the date in your computer or shifted repetitions backwards in time (e.g. with Mercy). Integrity checkup sorts the history of repetitions by date and reports this error if the sequence of repetitions is reversed. This error could have also been caused by errors in repetition numbering and in counting memory lapses but these should not normally occur


Repetition history errors may obstruct generating repetition graphs
(Beta, Germany, Feb 06, 2002)
Question:
In Browser : Tools : Repetitions graph I got this error: 
Wrong element in repetition history 
Found: Item #320: WIRKLICHKEIT is what you experience every day 
Expected: Item #6337: either (e.g. either of the two books)

Answer:
This problem should be resolved if you run File : Repair collection with Repetition history checked


Disappearing material
(hojinil, South Korea, Wednesday, April 11, 2001 4:29 AM)
Question:
I used Add New and I added lots of stuff but next time when I opened collections I couldn't find any of them. It was gone!
Answer:
Please make sure the following two conditions are met: 

  1. You are not copying or moving files behind the back of SuperMemo (e.g. with Windows Explorer) 
  2. With File : Open collection, you go to the exactly same location where you last left your collection 

If some files are moved or deleted behind the back of SuperMemo, it will often attempt to recreate missing files and open the collection regardless. Unless you delete your collection or delete its folders, your learning material should remain safe


Collection repair MUST NOT be interrupted
(P.N., Sweden, Fri, Apr 19, 2002 19:08)
Question:
If I quit SuperMemo the hard way (i.e. Ctrl+Alt+Del) during Repair collection the collection is damaged beyond repair
Answer:
File : Repair collection
is an all-or-none process. For the sake of speed, individual operations are not transactional. The whole recovery is considered a single transaction. You should back up the learning material if you are running it on valuable material that have not long been backed up. You MUST NOT ever interrupt recovery manually. SuperMemo is rebuilding many files and this process cannot be interrupted. It can be compared to CDR recording, once the process is disrupted, the CDR is toast. Figuratively, recovery is like carrying a car over a river. It might be safer to dismantle the car and carry each part separately, but it is faster and simpler to carry the whole car at once. With the backup checkbox, you can safely leave an exact copy of the car on the river bank


Some errors are not repaired at recovery
(J.P., Germany, Sun, Apr 21, 2002 10:00)
Question:
Why aren't some file errors not corrected at File : Repair collection?
Answer:
Some errors are best reversed by user action. For example, if you disconnect the secondary storage, SuperMemo will report many "missing file" errors. If it was to fix these errors (e.g. by resetting the filespace pointer), you would not be able to point to the correct secondary storage. If you restore the correct secondary storage, however, these errors will be gone


Support for the UNC notation is limited
(Michael Lapsley, United Kingdom, 24/04/2002 09:49:43)
Question:
SuperMemo has just displayed the following error: "Invalid destination: Error #123 Path: \\DELL"
Answer:
Although SuperMemo 15 does support the UNC notation, it does not do it in all possible contexts. Therefore, if you get this error you will be able to resolve it by assigning a drive letter to your UNC path (e.g. h:=\\DELL), and then use the drive letter to refer to network resources (e.g. h:\elements)


SuperMemo 2000 keeps changing my keyboard
(Elif & Brian, Tuesday, April 30, 2002 10:13 AM)
Question:
I'm using Windows 98. Whenever I cut some text (even plain text), and paste it into SuperMemo, it changes my keyboard from English to Turkish
Answer:
Unfortunately, this is most likely caused by a problem with your Windows. SuperMemo executes a very simple paste call to Windows that has nothing to do with the keyboard. It does not do any action that, in any remote way, could possibly change your default keyboard setup. Please try to inquire among user groups related to multinational support in Windows 98


Prohibited access error may indicate deleting registry objects that are still in use
(Xavier, Tue, Jul 17, 2001 17:13)
Question:
SuperMemo has just displayed the following error: 
   "Font registry access error! 
    Prohibited access 
   Position=1 
   LastPosition=0
"
Answer:
Most likely cause of this error is that you have used a registry font in an element in your collection and then you have deleted that font from the registry. If you later try to access this font within the element, the above error will be displayed. It means roughly "You are asking for font #1 while there are 0 fonts in the font registry". You should run File : Repair collection with Rebuild registries checked


Prohibited access may indicate collection errors (#7054)
(John Marchand, Belgium, Sun, Sep 30, 2001 16:20)
Question:
SuperMemo has just displayed the following error: 
"Text registry access error! 
Prohibited access 
Position=-2066493355 
LastPosition=3468
"
Answer:
Please run File : Repair collection with Rebuild Registries checked. For unknown reasons, SuperMemo tried to access a text listed on a negative position. All position in the registry are positive (in this case, there are 3468 members). If you recall how you arrived to this situation, please write back. This may help tracking a bug (if any)


Total-vs.-Memorized mismatch is indicative of serious data problems
(John Meacock, Wed, Sep 26, 2001 15:49)
Question:
SuperMemo has just displayed the following error: 
"Fatal error! 
Total is less than Memorized 
Total=13 
Memorized=21
"
Answer:
This error may indicate physical damage to your collection (e.g. when power failure occurs while writing data to the disk). Data in the .kno file has been corrupted. File : Repair collection is likely to repair the damage if it is limited to the KNO file, but similar errors occur only in cases of hardware failure, virus, computer crash or serious errors on the part of the user (e.g. copying one collection over another, etc.). Consequently, the damage may be wider that indicated by this message


Deleting use statistics from "the future"
(P.M, Tue, Apr 16, 2002 11:10)
Question:
Why did I get the message: 

This collection has already been opened with a later date! 
Do you want to delete use statistics from future dates? 
Today is 4/16/02 (Tue) 
Latest statistics come from 5/15/02 (Wed) 

I did not change the system date!
Answer:
It is enough you change the system date once to see this message. Once you open SuperMemo with a wrong date in the future, it will propagate use statistics up to the date of opening on the assumption that you took a long break from learning. If you reopen again with the correct date, it will detect data stored "in the future" and will ask you to confirm deleting this data. You will also see this message if you open "in the past". Respond with "No" and set the correct date. Otherwise your use statistics will be deleted


Redirected registry reference
(Beta, Apr 20, 2002)
Question:
Why is my collection displaying this annoying message: "Redirected registry reference"?
Answer:
SuperMemo 2002 or later makes it possible to redirect registry members. This way you can have two members point to the same registry data. The redirection occurs if you merge two members (e.g. by rename with the same target name). The message "Redirected registry reference" is displayed only in the debugging mode (Tools : Options : Access : Debugging version). The message will disappear if you switch the debugging mode off. You can also eliminate the message by running File : Repair collection with Rebuild registries checked. Registry rebuild eliminates all redirections (i.e. all redirected references are replaced with direct registry links)


Error in accessing sound registry
(J.Anastasi, 4/6/2002 2:51:39 AM)
Question:
What does this error mean:
Sound registry access error! 
Prohibited access 
Position=15 
LastPosition=0
Answer:
This error indicates that your sound registry does not exist (i.e. has been deleted). The LastPosition field indicates the count of registry members which is zero here. Some most likely causes of this error: 

  1. deleting the registry in error (e.g. by deleting SuperMemo folders manually) 
  2. locking the registry (e.g. by a failed Windows process) 
  3. trying to open the registry on CD-ROM (read-only) 

This error is serious enough to recommend that you restore your damaged learning material from the most recent backup


Error: Total<Memorized
(Wladimir Nossel, 4/13/2002 1:45:20 PM)
Question:
SuperMemo has just displayed the following error: 
"Fatal error! 
Total<Memorized 
Total=82 
Memorized=85
"
Answer:
This is a serious error that indicates a major problem with your collection. Most likely reasons: 

  1. computer crash during file operations 
  2. errors in restoring a file backup 

The discrepancy occurs between files *.kno which stores the number of memorized elements, and elinfo.dat which determines the size of the collection. If you restore elinfo.dat from a backup that is older than your *.kno file, this error could occur. 

Back up your learning material and run File : Repair collection. Review your learning material carefully as the above error may be associated with other serious integrity problems (including loss of the element content). If you are not sure the whole learning process has been restored successfully, resort to your most recent backup. 

Important reading: Backup and Recovery


Cannot get first interval approximation
(B.D., Poland, 2002-04-17 20:59:27)
Question:
What is the error "Cannot get first interval approximation"?
Answer:
Probably, the data has been corrupted in the file that keeps the track of your learning progress. This file is sm8opt.dat. This could have happened if you, for example, turned off the computer while SuperMemo was writing to this file (e.g. during repetitions). This could have also happened for any hardware or software reasons that result in changes to data files on your hard disk. You can copy sm8opt.dat file from one of your most recent collection backup. This way only a small fraction of data stored there will be lost. The learning process will not be affected visibly. If this does not help, you can use Tools : Statistics : Reset parameters : Optimization matrices to restore the file to its original state. This will, however, mean that SuperMemo will again have to collect data to better understand your memory. To quickly view the state of sm8opt.dat file, use the Analysis dialog box and inspect the Matrices : RF matrix. This particular error could arise if data in the first row of that matrix was corrupted (e.g. set to zero). For that reason, you could also peek at Graphs : First interval (see the normal shape of this graph here)


Multiple filespace entries
(Pascal Heimlicher, Switzerland, Sat, Nov 24, 2001 17:30)
Question:
SuperMemo has just displayed the following error: 
"Multiple filespace entries at: C:\Dokumente und Einstellungen\Pascal Heimlicher\Eigene Dateien\Archiv\Wissen\SuperMemo Lerndateien\Wissen\elements\8"
Answer:
The most likely reason for this error is adding filespace entries (e.g. images) with no access to secondary storage (e.g. CDR with other images, HTML files, etc.). This error can also occur if your computer crashes during filespace operations (e.g. deleting pictures, sounds, etc.). The problem can be remedied by running File : Repair collection with Verify filespace checked. Overlapping files will be separated. Stray filespace objects will be moved to a separate folder named: Recover. You can inspect that folder to see if removed files do not belong to important learning data. SuperMemo 2002 or later uses advanced filespace slot management that prevents errors in case of disconnecting the secondary storage


Use File : Repair collection in case of trouble
(Abdul Ghani, Singapore, 12/02/2002 15:17:49)
Question:
I was running SuperMemo when my computer restarted on its own. After that my whole collection is gone. Please advise me how I can recover it
Answer:
You need to do two things: 

  1. Backup your files
  2. Recover the learning material

If you are unable to complete the recovery on your own, send your collection for inspection and further help


Registry files errors are very dangerous
(Willem Brugmans, 12-1-2002 18:12:01)
Question:
SuperMemo has just displayed the following error: Fatal error! Cannot open registry files Registry=D:\supermemo2000\systems\WillemEigenSpaans\registry\tasklist. File not found
Answer:
Registry file errors are very dangerous. You should immediately back up your learning material and run File : Repair collection. In your case, "File not found" error might indicate there were some errors in copying your collection or it was wrongly restored from a backup. Manual changes in files could also cause similar problems. The registry in question here is the tasklist registry which does not hold learning material data. Nevertheless, you should carefully watch for similar errors in the future. At worst, please send your learning material to bugsYEAR(at)supermemo(dot)com for inspection


Wrong component data
(Bern Sadler, Australia, 20/02/2002 4:23:00 PM)
Question:
SuperMemo has just displayed the following error: 
"Component data loaded to wrong element 
Source=799 
Destination=798" 
This message has shown up perhaps 20 times in the last 2-3 days
Answer:
This message indicates that component data, which for safety is marked with the using element number, has been loaded to another element. This should not happen in normal circumstances. Most likely one element's data was loaded into another element or an element lost/redirected its component data pointer. It is very difficult to say how this could have happened otherwise than through a bug or a system instability. Nevertheless, this remedy will most likely cure similar cases: 

  1. Backup your collection (e.g. with File : Copy collection
  2. Run a system checkup with File : Repair collection

"Cannot create registry" is most likely caused by a file lock
(Grzegorz Knapczyk, TV, 2002-09-03 15:18:24)
Question:
SuperMemo has just displayed the following error: 
Cannot create registry 
F:\poradnik_m\SuperMemo2000\systems\ABC\registry\ole
File access denied

Answer:
"File access denied" error is most likely caused one of the two reasons: 

  • one of the registry files is set as read-only. In this case remove the read-only attribute from that file (and other files in the collection). This could, for example, have occurred after copying your collection from a CDR 
  • one of the registry files is locked by Windows. In this case restart Windows. This error could have happened as a result of a software crash (incl. SuperMemo crash) while SuperMemo uses the locked file

If the above does not help, restore the collection from the backup. If you do not have a backup, you can delete the whole ole registry and run File : Repair collection (you will lose all OLE objects in the collection)


Reinstalling missing Windows modules
(Tom Flahive, Sunday, September 29, 2002 2:54 AM)
Question:
I have tried to install SuperMemo 2002 and received the following message: "Please reinstall the following module to your system32 directory; KEYBOARD.DRV". The title of this dialog box is "NTVDM KERNEL: Missing 16-bit system module"
Answer:
Unfortunately the message indicates that your Windows installation is incomplete or corrupt. It is recommended that you run a virus check (keyboard.drv is a frequent target of viruses). You will probably need to reinstall Windows. Installing over the present installation will probably suffice


You cannot open the same collection with two instances of SuperMemo
(kimiyuki shirai, Japan, 2002/02/15 11:47:59)
Question:
SuperMemo has just displayed the following error: 
"Access denied! 
System locked by another SuperMemo: 
c:\Documents and Settings\All Users\fXNgbv\supermemo\systems\PERL.KNO"
Answer:
This message should warn you that a collection is already in use (with another instance of SuperMemo in memory). This is no indication of trouble to come. SuperMemo will simply let you open the next collection from the file pick-list


SuperMemo error: Error saving toolbar data
(Mike Condron , 4/27/2003)
Question:
I had to move my SuperMemo files from my laptop to my desktop (hard disk failure) and now I am frequently seeing this when I try to go to the Workload window: "Error saving toolbar data"
Answer:
See if SuperMemo can write to <SuperMemo>\bin\layout.ini file (e.g. try manual editing). This file stores layout of windows in SuperMemo. If the file is locked, the above error will recur (usually with Unable to write to C:\SuperMemo\bin\layout.ini", etc.). Most frequent reasons of file locks are: software crashes (restarting Windows solves the problem), file attribute changes and anti-virus software (some packages lock writes to INI files). See also if MSN Desktop Search is not locking this file while indexing


SuperMemo cannot read write-protected files
(Josef Chmelar, Czech Republic, Saturday, September 29, 2001 1:32 PM)
Question:
I created a backup on a CD-R. Unfortunately, SuperMemo displays: 
"Cannot reload HugeArray from C:\DOKUMENTY\SOUKROMé\DEPO\GRAMATIKA A VeTY\info\history.dat 
File access denied
"
Answer:
This error indicates that SuperMemo cannot read the files in your collection. Those files are probably marked as read-only (after copying from the CDR). You need to remove read-only attribute from all files used by SuperMemo. 

In some circumstances, certain files can be locked by Windows. This lock can be caused by SuperMemo or by other applications or processes. Restarting Windows should unlock the file. If this is the case, run File : Repair collection to scan for possible errors resulting from the file lock (SuperMemo might have been unable to update collection data)


Cannot select a new branch into a category (#15028)
(Jiri Pik, Germany, 1/3/2003)
Question:
SuperMemo displayed this error: "Cannot select a new branch into a category"
Answer:
This is the only report of this error so far. It could only have occurred as a result of problems with writing to the category file. In similar circumstances, error trapping around the offending procedure is boosted so that future versions could better diagnose the reason. Most likely, you should be able to repeat the same procedure after restarting SuperMemo. In a worse case, you may also need to log off from Windows (it this was a system-wide problem or the category file had been locked). In both cases, it would be prudent to run File : Repair collection with full registry checkup. Problems with writing to files often leave SuperMemo collections in an inconsistent state, which may result in future errors


Wrong size of the pending queue: Total less than Pending
(higgy33, 1/6/03 9:55:54 AM)
Question:
SuperMemo has just displayed the following error: 
"Fatal error! 
Total<Pending 
Total=44 
Pending=47 
C:\Program Files\systems\Logic.Kno"

Answer:
This error indicates a discrepancy in data stored in the collection. Most likely reasons for this error are: 

  • computer crash during file operations 
  • errors in restoring a file backup 

The discrepancy occurs between the file *.kno (in your case: Logic.kno), which stores the number of pending elements, and pending.dat which determines the size of the pending queue. If you restore *.kno from a backup that is older than your pending.dat file, this error could occur. Back up your learning material and run File : Repair collection. This should recreate the pending queue, and update the statistics


"Invalid filename" error occurs outside SuperMemo
(Peter , Netherlands, Mon, 12 May 2003 23:20:09 +0200)
Question:
I received the following message: 
Error: Cannot open file: 
C:\Program Files\Supermemo\systems\Family & Friends\info\workload.dat
Invalid filename
Answer:
"Invalid filename" problem occurs beyond SuperMemo and may have a number causes. First you can simply try to restart Windows to see if the problem is not transitory. If it reoccurs, you may need help from a software expert to check your drive mapping, file version synchronization, etc. In any case, as long as SuperMemo cannot access workload.dat file, you will certainly not be able to work with your Family & Friends collection. File : Repair collection will not work either as it also requires access to files for successful completion


You can easily reinstall SuperMemo
(Paul Turner, Canada, Wednesday, July 31, 2002 3:56 PM)
Question:
I have a new collection that crashed. I tried repair collection but the error message still comes up. Can I uninstall, reinstall and start again from scratch?
Answer:
Yes. You could delete SuperMemo folder and reinstall the downloaded file. You could also move SuperMemo to a new folder (the file name is sm15.exe) and simply run it. The program does not require the installation process


Error releasing hint window handle
(Carine VanLierde , Belgium, 2/02/2004 22:05:14)
Question:
SuperMemo has just displayed the following error: "Error releasing hint window handle"
Answer:
This error should be transient. It is likely to have been caused by a major system-wide instability. Restarting Windows is recommended. It is highly unlikely to result in any loss of data. Please report if it occurs again. Your report is the first ever of this error occurring


Cannot fit Grade-vs-ForgettingIndex curve
(Campbell Gunn , 03.05.26)
Question:
SuperMemo displayed this error: Cannot fit Grade-vs-ForgettingIndex curve
Answer:
This error indicates that the data describing your memory, and stored in sm8opt.dat file has been corrupted (e.g. filled with zeros during a system crash), etc. You can replace sm8opt.dat with an earlier backup of this file. You can also replace it with an un-initialized sm8opt.dat taken from an empty collection; however, in that latter case, SuperMemo will have to begin from scratch the effort to understand your memory. As there is no redundancy in storing this data, File : Repair collection will not be able to recover data that had been lost. Alternatively, you can also try using Tools : Statistics : Reset parameters : Optimization matrices


Element beyond the end of the collection
(Pete TerMaat , 7/16/2003)
Question:
What do I do about this error? 
Element beyond the end of the collection 
Element: 234 
Last element: 233
Answer:
This problem is an indication of errors inside your learning material files. SuperMemo tries to display element number 234, but your collection files physically include only 233 elements. If you run File : Repair collection, this error is likely to be fixed depending on the source of the erroneous element number (i.e. 234 in your case). The most likely reasons for this error are: 

  1. major software crash (e.g. at the moment of creating element #234 before it was physically written to the disk)
  2. mixing up files from an older backup and a newer version of the same collection (here the two collections might have included 233 and 234 elements)

Among 5 cases in 6, this error indicated a one-element difference that might lean towards Explanation #1. If the difference is larger than one, Explanation #2 is more likely


"Cannot write all data to Kno file" error may indicate a serious problem with hardware
(Troy Gardner, 11/2/2002 9:42:05 AM)
Question:
SuperMemo has just displayed the following error: "Cannot write all data to Kno file"
Answer:
This is a serious error indicating problems with writing to the hard disk. Back up your data immediately and run a hardware check on your computer. It is also highly likely that your present learning material has already been damaged. Try to use another PC and run File : Repair collection with all options on to make a full diagnostic. Technically, the failure occurs at the lowest level while executing a call to Windows _lwrite() function. This simply indicates Windows cannot complete data write with the selected set of parameters. This call is executed while trying to save program's vital learning statistics in the KNO file


Error trying to link a registry member
(Marek Wilmet , Poland, Tue, 23 Dec 2003 13:13:47 +0100)
Question:
SuperMemo has just displayed the following error: 
Error trying to link a registry member 
Access violation at address 00404BC1 in module 'sm2002.exe'
Read of address 0000796C

Answer:
This error may occur when you try to connect a registry member with a component. This error is unlikely to occur in normal circumstances when working with SuperMemo. It is more likely to occur as a result of earlier errors or bugs in SuperMemo or as a result of a system-wide problems with allocating windows resources. In the future, SuperMemo will display a more specific message that will help us track the context of this error. Most importantly, this error is unlikely to result in loss of data. It should disappear as soon as you restart SuperMemo (at best) or restart Windows (at worst)


Error simulating repetitions
(Michael , 12/25/03)
Question:
When trying to simulate future repetitions in SuperMemo, I received the following error: Error simulating repetitions on day 7 Range check error
Answer:
This is a bug in SuperMemo. It occurs when you execute the simulation procedure in the last days of December (each year). If you repeat the procedure on January 1 or later, this problem will not occur. It will also be solved in all future releases of SuperMemo


SuperMemo error: Cannot open registry files
(Kristof De Clercq, Apr 17, 2005, 05:18:09)
Question:
SuperMemo displayed the following error: 
Cannot open registry files 
Registry=C:\Program Files\SuperMemo\systems\ABC of SuperMemo 2004\registry\text 
I/O error 32
Answer:
I/O error 32 indicates a sharing violation. In your case, the text registry files have been locked, most probably by a crash during write operations or another application trying to access the files (esp. text.rtx). Those applications might include anti-virus software, indexing services (e.g. MSN Desktop Search), or even a dictionary. You should restart SuperMemo and restart Windows, backup your collection and run File : Repair collection. This error can but does not have to result in data loss (depending on when it occurs).
If you suspect that another application might be accessing and locking SuperMemo files, start Windows in Safe Mode and run SuperMemo. Then try to gradually turn on other applications to see which one might be the culprit


Errors after changing the date
(Simon, Apr 08, 2004, 08:52:23)
Question:
Something went wrong with our computer and the dates were reset. We put the dates back to the correct dates and now get the following 2 messages appearing every time we try to learn an outstanding repetition "Cannot get first interval approximation" "Cannot fit grade-vs-forgetting curve"
Answer:
Some older versions of SuperMemo included a bug that could ultimately result in damage to a file sm8opt.dat (INFO folder of the collection). Damage to this file may produce exactly the errors you quote. The simplest workaround is to take the sm8opt.dat file from your latest backup and substitute it in your present collection (or use Tools : Statistics : Reset parameters : Optimization matrices). However, it is also possible you may have had the date set wrongly while learning previously. Here the solution is to set the date back to the wrong setting used previously (if the difference in time was large, e.g. months/years), or work the difference out if the difference is not large. If the wrong date was too early, you could simply use Mercy and/or Postpone to spread out the outstanding work. If the wrong date was too late, you could use Mercy with Consider future repetitions to collect future repetitions, move them to earlier dates, and dilute the learning process


Error setting text selections
(Art Tsay, 2002/3/16 AM 11:43:51)
Question:
SuperMemo has just displayed the following error: 
   "Error setting text selections 
   Selection requested=221 
   Selection received=220"
Answer:
This error is harmless. It informs you that SuperMemo had problems with setting text selections (e.g. in incremental reading). Occasionally, you may need to reedit the resulting text (e.g. if it gets extracted incomplete). Otherwise, no action is necessary. If you are using Windows 2000 or Windows XP, you may reduce the occurrence of this error by using RTF filters (F6 shortcut). This is particularly useful if you are pasting rich text from the web


Error setting HTML selection (#15032)
(Anatoliy Lipatov, Ukraine, Monday, January 20, 2003 2:19 PM)
Question:
SuperMemo displayed: 
Error setting HTML selection 
Start=0 
Length=1 
Could not complete the operation due to error 800a025e

Answer:
This is a harmless error that occurs internally in Internet Explorer. It occurs when SuperMemo attempts to select text in an HTML file. This error is more frequent on files with tables or rich in multimedia. A good remedy against this problem is to use HTML Filter with F6 (Text : Convert : Filter on the component menu). You are also far less likely to see this error if you install the newest version of Internet Explorer (e.g. IE7 is far less buggy in that respect that IE6).

Optional: This is a bug in Microsoft's mshtml.dll. The exact code used in SuperMemo can be seen here (procedure TWeb.SetSelection)


This type of selection cannot be processed
(Bert Schouteten, 3/08/2003)
Question:
SuperMemo has just displayed the following error: 
  This type of selection cannot be processed 
  Access violation at address 0065850A in module 'sm2002.exe'. 
  Read of address 00000000
Answer:
This is a harmless error that occurs in HTML components whenever the component cannot correctly generate a text selection (e.g. for the purpose of extracting the fragment in incremental reading). The reason for this problem is probably a bug in Microsoft's mshtml.dll library, which does not handle well selections of certain multimedia content as well as tables. Unless you use a heavy multimedia files, this error should not occur. However, you can minimize the risk by: (1) importing stripped contents (e.g. article's texts without advertising), (2) using HTML filter (press F6 in the HTML component), or (3) converting multimedia HTML to simpler format (e.g. by pasting through your word processor). Unfortunately, rich multimedia, scripts and tables are well-known to cause a number of errors. None of these errors has been documented as resulting in loss of data. Instead of "Access violation" this error can also be a result of "Unspecified error"


Prohibited access in Image registry
(Aleksander Pronkiewicz, Poland, May 21, 2004, 13:05:54)
Question:
SuperMemo has just displayed the following error: 
   "Image registry access error! 
   Prohibited access 
   Position=43831 
   LastPosition=64"
Answer:
Usually, this error indicates that you have deleted a registry object (here an image) that is used in one of your elements. However, as you seem to have fewer than 64 images in the collection and the missing object is listed at position #43831, it is more likely that erroneous data has been stored in the place that should keep the pointer to the image registry object. The reasons for such errors in data can be many. Most of these are various forms of software and hardware crashes. To eliminate the problem and ensure no other data in your collection has been similarly affected, run File : Repair collection with Rebuild registries checked. Warning: This process may take a few hours for larger collections.


Illegitimate CD-ROMs may fail to install SuperMemo correctly
(Justyna , 2002-08-25 13:40:01)
Question:
SuperMemo has just displayed the following error: 
"Optimization record is set as read-only 
F:\Mindmanagers\Supermemo2000\systems\ABC\info\sm8opt.dat
"
Answer:
The file's attribute has not been changed from read-only upon the installation. Please check the legitimacy of the source of your CD-ROM. Original SuperMemo CD-ROMs use a different installation procedure


Problem with keyboard shortcuts
(Steve Brown, Sunday, October 13, 2002 4:05 PM)
Question:
When keying in a new Q/A pair, I type in the letter "c" it seems to be interpreting it as Alt+C and brings up the Contents window. When I type an "i", it brings up the History window as if I had pressed Alt+i
Answer:
This problem may occur in some older installations (e.g. Windows ME, Internet Explorer 5.5, national versions of the operating system, etc.). Your first optimum step would be to update your Internet Explorer 6.0. If you use older Windows and this does not help, you can simply remove shortcuts from the interface by means of Tools : Options : Language : Localization table (removing all ampersands: "&"). A ready-made language interface is also available as trimmed.tra. If this all seems too complex, you could also try this procedure


Error disposing of component buffer memory
(Sanju Midori, Japan, May 04, 2005, 09:32:34)
Question:
SuperMemo has just displayed the following error: 
Error disposing of component #3 buffer memory
Answer:
This error will occur only as a result of a previous crash or event that corrupts data SuperMemo keeps in memory. This error is not dangerous on its own. It only affects data kept in memory without writing anything to the collection on the disk. However, it is indicative of a problem that might or might not result in data loss, and/or might or might not result from corrupt data. This is why you should backup your collection and run File : Repair collection with Rebuild registries checked. 

Technical: This error occurs when SuperMemo begins to dispose of memory allocated for component data of a given element, e.g. when moving to a new element, and discovers that the memory has already been disposed by another thread. There were three reports of this error occurring in SuperMemo 2002 and SuperMemo 2004, each time in the context of major instability (i.e. a series of error events in the wake of software malfunction). It is possible that this error is a result of data storage errors. See also: SuperMemo error: Error freeing component


SuperMemo error: Error freeing component
(Pat Meakin, May 07, 2005, 18:23:23)
Question:
SuperMemo has just displayed an error: 
"Error freeing component #1 
Access violation at address 00000000. Read of address 00000000"
Answer:
This error will occur only as a result of a previous crash or event that corrupts data SuperMemo keeps in memory. This error is not dangerous on its own. It only affects data kept in memory without writing anything to the collection on the disk. However, it is indicative of a problem that might or might not result in data loss, and/or might or might not result from corrupt data. This is why you should backup your collection and run File : Repair collection with Rebuild registries checked.

Technical: This error occurs when SuperMemo begins to dispose of memory allocated for a visual component control of a given element, e.g. when moving to a new element, and discovers that the control has already been disposed by another thread. This error has been reported only once for SuperMemo 2000 four years ago. However, other errors with disposing memory may mask this one in similar circumstances (compare: Error disposing of component buffer memory)


SuperMemo error: Error upgrading RTF to HTML
(Francis Harding , 4/9/2003)
Question:
I received the following message: "Error upgrading RTF to HTML: Cannot open clipboard"
Answer:
This rare error may occur while opening RTF texts in HTML components at the time when the clipboard is locked (e.g. immediately after copying large portions of text). For example, this may happen when you apply HTML template to an RTF-based element. This error may result in the following problems: 

  • conversion of an RTF text to HTML will not take place 
  • (most likely) an RTF text will be replaced with a plain text 
  • (unlikely) an RTF text will be lost (i.e. replaced with an empty string) 

All these cases are local (i.e. only the presently displayed element is affected) and recoverable. If the problem occurs while applying a template, the first thing to try is to detach the template and repeat the operation. In rare cases, in which you had lost formatting or the entire text, you can recover the text file from the collection's TEMP folder (e.g. if your collection is named Egypt.kno, the copy of the text that is being converted is kept in the file Egypt/temp/temp.rtf, and remains safe until you move to processing other RTF components)


Problems with pasting texts
(Elliott Mayo, Thursday, October 24, 2002 3:09 AM)
Question:
I have 3 components: text, HTML, and sound. Only the HTML has an entry. I cannot always cut and paste from the HTML component to the text component. I do a copy, and when I paste, nothing is pasted
Answer:
This is a known issue with some Windows installations. This is a system-wide problem and may affect SuperMemo as much as other applications (e.g. Internet Explorer, MS Outlook, etc.). The bug is with Microsoft components. In your case, the most likely reason is a problem with the HTML component which is based on the notoriously buggy mshtml.dll library included in Windows. In most installations, this problem does not occur. However, if it does, installing the newest Internet Explorer often resolves the issue


Error pasting from keyboard
(Hjp2304, Saturday, March 15, 2003 11:20 AM)
Question:
When pasting from the clipboard the following code from MAPLE 2 * 1.08/1.12 + 2 * 1.08^2/1.12^2 + 2 * 1.08^3/1.12^3 + 2 * 1.08^3/ (.12 - .04) * 1.04 / 1.12^3; 28.89413266, I got error message "access violation at the address 71ce2d59 in msconv97.dll, read of address 0"
Answer:
Unfortunately, this error occurs outside SuperMemo. When you paste your text, Windows text conversion library is invoked (msconv97.dll). The above error is internal to that library. Some Windows installation notoriously replace that library with an older version. This results in some compatibility problems. Some of these can be resolved by using an in-between word-processing application to paste and re-paste your text (even Windows Notepad can be useful for re-paste purposes)


Error adding new text topic. Cannot open clipboard
(Jiri Pik, Jul 27, 2004, 07:32:16)
Question:
SuperMemo reported: 
"Error adding new text topic. 
Cannot open clipboard
"
Answer:
When applications do operations on the clipboard they need to lock it (to prevent other applications using the clipboard at the same time). In your case, SuperMemo tried to paste the article at the time when clipboard was locked. The following might have caused the situation:

  • you are pasting a large or complex article that takes longer to copy (repeat the paste to succeed)
  • another application locked the clipboard (see which or wait)
  • an application locked the clipboard permanently while crashing (at worst, restart Windows)

Wrong component buffer marker
(Willem Brugmans, Monday, December 09, 2002 11:53 AM)
Question:
SuperMemo has displayed the following error 
"Wrong component buffer marker 
File=E:\SUPERMEMO\SYSTEMS\EspańolHablado1\info\compon.dat 
Position=166712
Item #1399: RöG: Was war den Römern im 2. Vertrag mit den Karthagern an der span. Küste, auf ..."

Answer:
This is a very serious error indicating a major problem with your learning material files. You should do the following as soon as possible: 

  1. backup your collection into a safe location 
  2. verify collection integrity with File : Repair collection
  3. review the collection (e.g. by using F11 to scan as much of the learning material as possible)
  4. check your system for hardware problems, viruses, etc.
  5. verify if you correctly handle SuperMemo files (see: Backup: protecting your investment in learning)