Since Poser Pro 2014, the mat room has randomly rejected and accepted both mp4 and mov formats - meaning one day the mov works, and the next day it doesn't (or sometimes mere minutes). In this instance, I am using mov. ( one of the issues i have had that support has tried to, but did not resolve).

Your second thought may be closer to the issue. However I don't know how to address that. All the settings appear to be the same; mat room, lights, cameras. I usually have the gamma turned off. Maybe if I turn it on...I will try that. Any other ideas?

Thanks for your input!