Try opening outlook in the safe mode by going to start > run > outlook /safe
and see if the issue occurs if it does not then can be an issue with the
addin or else try clearing the form cache under tools > options > other >
advanced > custom forms > manage forms > select the personal forms and clear
the cache.
I am running outlook 2000 and I do not have the path that you suggest to
clear the forms cache. Is there another way? I am getting the error in both
safe mode and regular mode.
Can you try searching for the file frmcache.dat and rename the same to
frmcache.old.Also try doing a detect of office.You could also post your
entries to microsoft.public.outlook
Hope this helps