Thank you. That solution technically worked, although it seems that it would require some workarounds to make it practically useable. Looks like I will have to rethink how I approach the problem for now.

Had the same problem (XCode Version 13.2.1 (13C100)). Here is a workaround: In the navigator select your app's Info (Info.plist). In the property list expand and go to: Document Types Delete the unwanted items in that array To reflect the changes in the App properties editor (the one in the screenshot posted in the question) I had to restart XCode. Might not be necessary, but for me that was the only way how to make XCode to reflect the changes.

I gave up, moved to AppKit. This question is no longer relevant.

Having the same problem with XCode Version 13.2.1 (13C100), regular application project on 2016 MBP (the problem seems not to be Catalyst nor M1 related). Tried: clean build folder restart computer reinstall XCode Neither helped. Only thing I noticed that all the *.dia files in the build folder have zero length. So whichever tool produces them must be crashing unexpectedly. EDIT: Noticed that it crashes only when an error is inside of a function. If an error is at the top-level structure (class, function signature, ...), then it is being reported as expected.

This seems to be fixed in XCode Version 15.1 beta (15C5028h).