EGP - UMSG can get stuck if user crashes before UMSG end message is sent

on EGP , if the client is inmidst a UMSG and crashes, causing a prop clear, the UMSG can get stuck and never get a proper end message, hanging every subsequent attempt to start a message from other users.

Might need a timeout function that runs serverside to cancel any umsg's that are hung for more than 5 minutes or so.
Unsure how it happened, only guess is that the client must have had a bad timing.