Here's something to try if none of the previous suggestions work (although use at your own risk!)... Locate your ....pbxproj file and make a copy, just in case anything messes up. Open the ....pbxproj for editing, search for productRefGroup and delete that line. Save the edit and re-open Xcode. Products directory shows back up! Summary: I'm not sure if productRefGroup is really necessary! Everything seems to build fine without it.

Check out: https://github.com/ethanhuang13/CupertinoJWT It works great, might be helpful for you!

I get this same error on latest Mac Catalyst, and similarly, the same code works perfectly on iOS in my case as well. This is specific to MPMusicPlayerController.applicationQueuePlayer (if I use .systemMusicPlayer instead, it does work on Catalyst... but systemMusicPlayer is not the behavior I want). Anyone else experience this? Should we submit it as a bug to Apple?