.mov files not playing in Photos
Why are all my .mov files not playing in Photos on my newly purchased iMac May 3, 2023.
However, all videos do play on my iPhone. (Both iPhone and iMac devices are synching ON.)
What is the status bar showing below the Library > All Photostab in Photos on your Mac? IPlease check the status as described here: Check the status of your library in Photos for macOS - Apple Support
Are there any problematic items listed?
Where is your Photos Library stored? In the Pictures folder or on an external drive?
What happens, when you try to play a video? Do you get an error message? If yes, what is the error message?