Zoom can "hang" when sharing a display with the ICM program.
When you share your screen when displaying images with the ICM program, you might find that screen freezes. This is some sort of incompatibility between the ICM program display and the Zoom program. We found nothing incorrect with the ICM program and are hoping that the Zoom program will correct this issue in the future.
The 'lock up" seems to happen when you use one of the Zoom control panels while hosting.
To exit the "lock up", use a left mouse click on an empty area on your screen and the system will recover.
This solution was provided by Dennis Tungate of the Livermore Valley Camera Club .