Clearing the cached forms may help. Search for frmcache.dat. Rename it to something else e.g. frmcache.dat2 (in the event you need it). Exit and restart Outlook - this may resolve the issue.
Also, the form may be open but hidden from view - due to being moved or minimized.
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.
