Disappearing Safari extensions

from blog The Desolation of Blog, | ↗ original
Since I released my Safari extension Tweaks for Twitter three months ago, I've received a number of bug reports from customers saying that the extension doesn't appear in Safari. And when my app calls the API [SFSafariApplication showPreferencesForExtensionWithIdentifier: completionHandler:] to show the extension in Safari Preferences, there's an error "SFErrorDomain error 1". This issue never happened with my other Safari extension StopTheMadness, which is three years old. The two extensions use different Safari extension API: Tweaks for Twitter is a Safari web extension, a newer API, whereas StopTheMadness is a Safari app extension, an older API. I've never been able to reproduce the issue with Safari web extensions myself until yesterday, so now I have more details to share. I suspect the reason I can now reproduce it is that I recently updated to Big Sur.