hello. I have the same problem but on WINDOWS 10 in Premiere and After Effects. I can't import .mov and .mp4. in AE I get an error:
'the following pluins have failed to load. please reinstall the plugins. ....media core plugins - ImporterMPEG.prm / ImporterQuickTime.prm / ImporterWindowsMedia.prm . In Premiere I can't load any mp4/mov and I get the file is not supported. everything is on a clean install on windows 10 and clean adobe!! I have also tried to install quicktime (latest version) and same shit.... im going crazy.
ok so I fixed both issues in Pr and AE
I have installed Windows 10 PRO N so I tried the adding the Media Features first thing and still did not work.
After installing the newest version (APRIL) all is fixed! finally....
here's the link
https://support.microsoft.com/en-us/help/4016817/media-feature-pack-for-n-edition-of-windows-10-version-1703-april-2017
hope it helps
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