When 5.4 was installed, did it update the APTPATH from 5.2 to 5.4 (i.e.
C:\Arbortext\Editor to C:\PTC\Editor)? Do you have apps dependent on
the APTPATH being set? When we moved to 5.3, I took those out of our
environment vars without any ill effects.
When updating from 5.1 to 5.3, I was seeing really strange behavior and
odd errors/startup times, and found that my old Arbortext.wcf wasn't
"valid" when 5.3 was trying to open it. Completely deleting it and
restarting Editor to generate a new one seemed to do the trick.
If your organization is anything like mine, standard users have little
to no access to write files to their C:\ drive. Is it possible you
might have a R/W issue?
Just trying anything I can think of at this point...