RAW file Quick Look broken in MacOS 15.4

It looks like Apple MacOS 15.4 (even the .1 patch) has broken Quick Look (using the Space key in Finder) for some RAW files from cameras, as the previews for .cr2 files from (somewhat) more recent cameras like my Canon EOS 5D Mk IV and my previous Canon EOS 5D Mk III now just show a black image with Quick Look, but using the main Preview app to preview them still works correctly.

Interestingly, Quick Look still does correctly display the contents of even older .cr2 RAW files from my original Canon EOS 5D (Mk I), so it’s likely camera-specific. Also, Finder thumbnails work correctly in all cases for me (i.e. even for .cr2 files that Quick Look doesn’t work with), so I’d guess it’s code-path-specific as well.

There are a few threads on various forums about this, so it doesn’t seem to be an isolated issue, but at the same time, some people don’t seem to be having the issue at all, and others are reporting different combinations of things working or not working.

It’s not the end of the world - but it is a bit annoying, as Quick Look is a very useful feature that I use regularly while copying and backing up RAW files from my camera to my NAS storage device.

Especially given how often MacOS was pestering me to upgrade to 15.4 with notification pop-ups most times I awoke/unlocked my MacBook Pro. I know, I know: security updates - but this is one of the reasons I’m very hesitant to apply Apple software updates in recent years, since in my opinion, their software quality has been on an unfortunate downward trajectory for several years, and fairly often things get broken or change for the worse (e.g. modern System Settings was a bit of a step backwards in usability IMO) as a result.

Edit on 17th May: It looks like Apple have just fixed this in MacOS 15.5!