Cannot Import HEVC .MOV File on Some Macs but Can Import on Others

Hi, I have some proxy files created by Atomos Shogun recorders. They are created as 720p HEVC with .MOV extensions. When I try to bring these into Premiere, the Import progress bar sticks at the very beginning and will not import. This happens on v24, v25, v26, and beta.

I can open the file just fine in QT Player and Avid Media Composer and Resolve import the files just fine.

I’ve tried re-installing Premiere. I’ve cleared my media cache and reset my Premiere preferences.

Here’s where it gets interesting. This issue is on 2 of my machines; but the files import just fine on many other machines I’ve tried. All Mac systems. MacOS 14 and MacOS 15.

And then to make things more interesting, if I simply change the extension to .mp4, the files import successfully on the problematic systems.

There must be a corrupt setting or codec somewhere but I’m at a loss of where to look. In my /Users/Shared folder, I have a AdobeInstalledCodecsTier2 folder that contains mc_enc_hevc.framework and mc_dec_hevc.framework folders and files. This was actually created when I changed the extension to .mp4.