As it's part of SIP, the alert will be suppressed if you disable SIP itself, but I don't like this workaround since it unnecessarily endangers my machine. However, I can't live with this alert. Not only does it significantly slow down development, but I also can't properly test the actual behavior. Technically, I could change the app to meet the criteria, but I wouldn't do that, as it would require writing migration code for CoreData, User Defaults, and other files in the Group Container for existing users. This would be a huge amount of work, including testing. I’m hoping that one day we’ll be able to include iOS-style app group IDs in the allowlist for macOS provisioning profiles, which will allow apps like yours to fall under criteria 3. However, today is not that day )-: I hope that day comes soon. It's ironic that this new security feature could end up encouraging people to disable one of the most important security layers.

In my case, the issue occurred after installing an app with the same bundle identifier that was installed through TestFlight. I removed the TestFlight version of the app, ran this command, and the extension appeared again: /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

@DTS Engineer Yes, I can replicate it on macOS 15.5 Beta 1 (24F5042g) as well.: FWIW, the macOS of my initial comment was Sequoia 15.4 (24E248).