Has this happened to you? Out of the blue, using Quicklook (normally with spacebar in Finder, for example) no longer displays correctly. Images show up as a small thumbnail with a thick white border. Many other files just show up with a place holder. Video files no longer play in Quicklook.
It ends up looking like this:
Surely Apple hasn’t killed the wonderful Quicklook feature?
Well, no they haven’t. It’s a bug (seemingly. And the fix is easy … and, ironically, to fix it, you need to kill the Quicklook feature. But only momentarily.
Solution to broken Quicklook in Monterey
For most people the solution is apparently very simple.
1) Open Activity Monitor (if you don’t know what that is, hit CMD-Space to bring up Spotlight search, type “Activity” into the Spotlight search, and select the Activity Monitor app that will be showing at the top of the search results.
2) In Activity Monitor, search for “Quick”. You should see an entry come up named “QuickLookUIService (Finder)”
Select that entry. Then click the X icon and select Force Quit.
Hopefully that’s done the trick.
Return to Finder and hit spacebar on an image, or video, etc. It should now show up in the fully functional Quicklook you are used to.