A mission that has been loading fine for months started to cause Client locks while loading on dev branch version 1.53.132942 and to any version after that.
Dedicated server and Headless client are still on line with no crash.
Reverted to standard NON-Dev version and problem goes away.
The mission starts loading, there is a brief refresh as if it is about to load the briefing map and then it goes back into the loading screen and stops there.
Client requires Control/Alt/Del or Alt-Tab to begin the process of exiting locked screen.
The mod showing on the rpt is just music/non intrusive code. Unchanged since before the issue appeared. {F27280} {F27281}