based in the description, it's hard to tell...
But: FMS 13 and FM13 are quite stable, no crashes here
Problem might occur with the Admin console for the server, with WebDirect - but FM Pro runs fine!
Thank you for your post.
It may help if you display part of the crash report that includes the crashed thread.
Do you know what users are doing prior to the crash? Are users experiencing the crash with a specific file?
Any other information you can provide may be helpful.