Sinbad The Sailor:
Thank you for posting.
You may want to consider whether there is a corruption issue with the database. This may be the case if the crashing occurs on any machine. You may want to try a recovery or saving a clone copy of the file to see if it also triggers the crash. Also try loading a backup copy to see if it behaves the same.
Is the application closing before the Sort window even appears? If it is only occuring on one machine, it could simply be a corrupt installation or preferences file.
Any information you can provide about the server and how the clients access it may also help. Is the database being hosted with FileMaker Pro or FileMaker Server? Does the crashing occur on a local copy of the database?