Another idea, in case @anon291708 suggestion doesn’t help.
When PT is locked up, get the user (with the least poor internet connection) to run:
C:\Program Files (x86)\Paratext 8\ParatextForceShutdown.exe
This will cause PT to close (If its already hung, this isn’t any worse) and send a problem report describing what PT is currently doing.
Please don’t run ParatextForceShutdown.exe unless Paratext has actually hung.