Hi Jacob
Our application is quite large and there would not be an opportunity to replicate outside of the PFC in any reasonable time.
Also, the App is not generally crashing. It just fails to display the windows(sheets) for some of the larger windows when selected and opened from the MDI Menu. Smaller apps similarly structured and based on the same PFC libraries appear to work fine. When we select the bigger windows the sheet never appears but the app behaves as if it is open and when run from the debugger I can click to go back to the code.
Our use of the PFC is basic, windows objects inheritance, resize, preference, and linkage services and has worked without a hitch up through 12.5 We've heard that windows resize can crash apps in PB15, but we are not exactly seeing a crash. We can try disabling some of the services to see if that changes anything.
Based on what I am seeing, I suspect that it has something to do with the MDI frame and Sheet behavior - an area that was worked on in PB15.
Best regards
Glenn