Do you use 3rd party plugins?
If you have updated from a previous version of FMP but have not kept the plugins up to date that can cause crashing.
More details about the server hardware and settings would make it much easier to help you.
We have crashes, but only on Filemaker exit. Filemaker's people are currently investigating the cause.
Disabling plugins is good idea.
1) Have you tried to recover your database?
2) When does the crash occur?
3) Do you have Windows machine? If yes, you can debug Filemaker with WinDbg and see more details.