Thanks for the input.
Also, you were saying that you copy the system to another dir and then change the PROPATH to the new dir and the users start moving over to the new system.
And the corrupt MSGF.pro at some point stops being corrput as the users log out??? Is that true??
Not quite. I copy the source code over to the new region (with people on the system). I then replace msgf.pro with a good version. Then, I change PROPATH and everything is fine for new logins - and the file appears stable. Given how crappy a solution this was, I didn't want to stress test it - because what would I do if msgf corrupted again?
So instead, I satisified myself that I could use this as a potential solution but asked the client to down the server and put the known good msgf.pro in "real" region.
Do you get any errors (going to @RFUNCT) within ProIV, trying to read MSGF (or just running screen functions), when the file is corrupt?
No @RFUNCT. Instead, just a lack of help and error messages. The help messages are gone and the error messages will only show E054 (for instance).
Is the file only corrupt, when users are logged in?
I don't have enough data yet to answer that. Hopefully simply downing the server and copy the file across will solve the problem... hopefully...