This part of the forum is intended for reporting possible software bugs.
Version 11 will open and convert the file to .fp7 format--the format used for versions 7 through 11.
I recommend that you read this Knowledge Base articles on converting your files:
Converting to .fp7 format: http://help.filemaker.com/app/answers/detail/a_id/750/kw/converting
Be prepared to invest some time into testing and updating the converted files as there is a good chance that your converted files may not function perfectly. The KB article covers many, but not all of the possible issues. Feel free to post back to the FileMaker Pro Forum (not here) with any issues you encounter that don't seem to have been covered by the KB articles.