Does that mean you were previously using an older version of FileMaker?
If so.... (I'm just speculating here, but my speculation is based on personal experience and what other have reported here.)
Your file may have already had a problem prior to your upgrade. Sometims one version of FileMaker or one version of your operating system will "tolerate" the problem and thus it is not apparent to the user that any problem exists. Then when you upgrade either OS or FileMaker, you get a crash or other indicators that something is wrong with your file.
Just to complicate things, the crashes that have happened since may have also damaged your file.
If you have a copy of your file that you have not opened in FileMaker 11, use Recover to run a recover on this file and see if any problems are identified. Even if no problems are identified, test the recovered copy to see if it is stable. (IF you do not have a back up copy, then you'll need to do this on your current copy, but now we can't be certain any problem identified came about before or after the crashes.)
Things to keep in mind about Recover:
- Recover does not detect all problems
- Recover doesn't always fix all problems correctly
- Best Practice is to never put a recovered copy back into regular use or development. Instead, replace the damaged file with an undamaged back up copy if this is at all possible. You may have to save a clone of the back up copy and import all data from your recovered copy to get a working copy with the most up to date information possible.