Have recently had frequent GPFs if I attempted to open more than single App file at once.
With a little investigation, I noticed that the template registry file would increase in size by 4K every time an App was opened or even when simply viewed using the template registry editor. Deleting the TemplateRegistry11.trf and re-registering 30 templates dropped the file size from 483,791K to 9658K.
While I remember there are long reported Clarion issues in this area, my oblivious existence clearly masked the severity for awhile. Happy to serve as a reminder to others now.