Using XOJO 2018R4
I have an app that shows some photos in a Canvas as preview.
High Sierra all nice and smooth , same code in Mojave is crashing the app straight with the error :
Date/Time: 2018-12-20 17:26:25.392 +0100
OS Version: Mac OS X 10.14.2 (18C54)
Report Version: 12
Time Awake Since Boot: 2200 seconds
System Integrity Protection: enabled
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Termination Signal: Illegal instruction: 4
Termination Reason: Namespace SIGNAL, Code 0x4
Terminating Process: exc handler 
Application Specific Information:
Crashing on exception: The window has been marked as needing another Display Window pass, but it has already had more Display Window passes than there are views in the window.
Any idea what this could be ?
So doing some tests , in High Sierra , the Modal window shows, loads the pictures and displays and all, while in Mojave same code is calling Paint event several it crashes with that error .
Did something changed in the last update related to Canvas ? and Mojave ?