You can't even open the file, correct?
Sounds like you have a script that runs when the file is opened.
If so, use a copy of filemaker advanced to:
1) launch filemaker without opening the file.
2) Enable the script debugger
3) Now use the file menu to open the file.
4) IF a script appears in the debugger, cancel the script.
If you don't have advanced, you may be able to open the file while pressing Esc (windows) or Option-period (mac). Sometimes that'll cancel the script in time.
You may have a damaged file. Try recovering it and see if you can open the recovered copy. If that's what it takes, you should replace your damaged file with a back up copy.
Thanks. I do have advanced.