I've got a group of schools using a FMP 7 database. In one building teachers are reporting that the Filemaker Pro app is quitting on them after someone else logs on to the data base. It is not giving any error message it just quits the app. When they log onto the database using their VPN connection it seems to fix the problem. Any suggestions?

Check the console for any clues in the various logs?

Make sure OS-level file sharing is turned off on the server. Users should only be connecting throgh the Open Remote (hosts) command -- or an opener file configured to do so.