Database is how old? Was it converted to FMP11? Number of records?
Crashes with error message? Has it crashed before this?
Save a Copy as Smaller, open and test export.
Save a Copy as Clone, add two or three records, test export.
You may need to recover the database and test the export.
Ideally, you would revert to a known good backup, import current records and continue.
There may be corruption in FMP's working files and a reinstall should remedy the problem.
It Resolved it self..... when I discovered that the print job I had going as well had stopped (printer Issue) as soon as I ckeared the spooler of the document..... must have been holding some stuff locked I guess