Hi,
When I updated to 10.15.7, on my mid-2012, my internet completely broke. I had to revert to factory settings. Before that, m4v files worked fine running VLC or QuickTime. Now they won't play. In quicktime they run choppy without sound. On VLC they have sound but no picture. I've searched and searched with no solutions. I've tried other video apps, I've tried renaming mp4, I've tried latest vlc. Nothing.
MacBook Pro 15″, macOS 10.15
M4V files with the following specs play OK on my Catalina iMac:
Open one in Quicktime Player and bring up the Inspector window and compare.
Boot into Safe Mode (How to use safe mode on your Mac - Apple Support) by booting with the Shift key held down and check there to see if the problem persists. Reboot normally and test again.
NOTE: Safe Mode boot can take up to 10 minutes as it's doing the following;
• Verifies your startup disk and attempts to repair directory issues, if needed
• Loads only required kernel extensions (prevents 3rd party extensions from loading)
• Prevents Startup Items and Login Items from opening automatically
• Disables user-installed fonts
• Deletes font caches, kernel cache, and other system cache files
Also log into another vanilla admin user account, Set up users, guests, and groups on Mac, and see if the problem persists. (This tells us if the problem is limited to your user account or is system wide).
Can you give us a screenshot of the inspector window?
I will try to those. The video size is much much larger than yours. However, they played just fine on this machine before reverting to factory settings.
That didn't work.
M4V video files not working on Mac anymore
