According to the Microsoft Knowledge Base, this error message occurs when users running Windows XP attempt to access a table with a memo field on a file server that is running Windows ME or earlier. The error arises from the differences in file locking in the different versions of Windows. (See http://support.microsoft.com/default.aspx?scid=kb;en-us;812696.)
In my experience, a much more likely reason for this error is simple file corruption. Typically, the system crashed, or the user switched off the computer, while a table with a memo field was open.
When this happens, the user will often be able to re-open the table and perhaps access its records, but certain operations û a Pack or a Reindex, for example û will produce the error.
Faced with this situation, hereÆs a simple fix:
1. Open the table exclusively.
2 Go into the Table Designer (for example, by typing MODIFY STRUCTURE).
3. Make a non-destructive change to the table structure. For example, you could increase the length of a character field by 1.
4. Pack the table.
5. Re-open the table, go back to the Table Designer, and undo the change you made in step 3.
I canÆt guarantee that this will always work, but it has saved the day for me more than once.