Hi,
I have experienced similar problems with Winnt running Diadem v8 (certainly the same error message and symptoms - correct operation for some time, then all of a sudden loss of user variables).
We have cured the problem (together with Ni) as follows:
When user variables are intialised (either from menu or an autosequence) 2 temporary files, in the default teporary directory, are created to manage them
av_indx.001 and av_info.001
these are swept when diadem closes.
The diadem variable tmpdrv holds the path - so it can be checked.
these files are not normally set to read only, however you may find that yours are. We summise that a machine/diadem crash causes the state to be changed.
deleting the files or changing file properties re
sults (for us at least) in a return to normal operation.
The error was probably generated as a consequence of diadem being unable to overwrite/delete the read-only temp files.
hope this helps
andy