Force quitting can possibly damage your file.
To check, launch FileMaker without trying to open this file. Then select recover from the File menu and select your file as the file to recover. What you describe could be a corrupted index so test the recovered copy even if the recover does not report finding any problems as recover rebuilds all indexes without trying to analyze them for problems.
Things to keep in mind about Recover:
While Recover almost always detects and fully corrects any problems with your file...
- The recovered copy may behave differently even if recover reports "no problems found".
- 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.
And here's a knowledgebase article that you may find useful: What to do when your file is corrupt (KB5421).