I'd use recover or FMDiff (3rd party utility) to check that file for damage. Sometimes a corrupted file will misbehave with one version of FileMaker and not another--which might explain why the file worked with FMP 10.
Thank you for your reply. I did run a consistency check and it did not find any problems.
I have now made a copy of the database and am doing a recovery on it. I will review the log details once it completes. The database is rather large and will take a while to complete.
Once again, thank you for your suggestion.