Close the database, then go to the bottom of the File menu and run Recover, and select your db. Once recovered, DO NOT use the recovered base if you can possibly get around that -- go to back up and grab what you know is a GOOD copy (prior to crash) of your db, Save A Copy As (select "clone (no records)"), and then import the data from your recovered base into that good clone of the db. Toss the recovered rev now and then you should be good to go.
If you do not have a backup, you will be forced to use your recovered version, and there may be probelms with that at some point...
Now, all of the above stated to CYA, I have not had that many problems using recovered bases (and yes, I have used them plenty of times -- I only found out about not using the actual recovered versions a couple of years ago -- prior to that I ~always~ used recovered version -- that was what I thought you were supposed to do!!!... and I have been using FM since 1989, so that's a while).