[quote='815622022, floorish, /thread/764435?answerId=815622022#815622022, /profile/floorish'] I've received multiple confirmations that any of these solutions resolve the issue: Create a new user account (old account will stay bugged) Reset the macOS keychain for the (bugged) user account Update to 15.1+ [/quote] Thank you SO MUCH for this. I've spent a TON of time investigating why, after updating from Ventura to Sonoma, Final Cut Pro 11 was being so terribly SLOW ( mainly when opening libraries and when closing the app ), even though FCP 10.8.1 worked fine! A clue pointing me towards this thread popped up, when I tried to use HandBrake to transcode a video and have encountered the very same problems as in FCP. Handbrake's console listed the following: [09:30:49] macgui: Failed to create bookmark: Error Domain=NSCocoaErrorDomain Code=256 "Failed to retrieve app-scope key" UserInfo={NSDebugDescription=Failed to retrieve app-scope key} [09:30:49] macgui: Failed to create bookmark: Error Domain=NSCocoaErrorDomain Code=256 "Could not open() the item" UserInfo={NSURL=file:///Users/######/Library/Containers/fr.handbrake.HandBrake/Data/Movies/, NSDebugDescription=Could not open() the item} The new user account also worked flawlessly but that was obviously not a solution. Nothing I did helped ( and believe you me, I've tried a ton of stuff, from re-downloading the app via app store, through launching it via a sandbox, rosetta, changing the permissions, ownership, flags, permissions via tccutil etc. to changing the user password, Mac's name and so on ) until I have resetted the macOS keychain. So if anybody else's looking for solution to apps suddenly being weirdly slow when f.ex opening files and/or when closing, this is it. Does upgrading from macOS 13 to macOS 14.7.1 break the keychain? Apparently so. I didn't do anything in particular when updating. I do recall that Software Update popped up an update for some XCode's tools - a version 1.0 and 1.1 - and I've installed only 1.1 though I'm not sure if this has anything to do with this. In any case, thanks again!