Hi!
I think I found what the issue was. So I read carefully the error message, and in my case it gave me 3 following errors: SKView warning logs, Metal API was enabled, and Metal GPU Frame Capture was enabled. As I found SKView error is SpriteKit's mistake that should disappear in new versions of XCode. The rest two errors I just disabled them in the Xcode Scheme:
" Product>Scheme>Edit Scheme>Options> Metal API Validation/ Metal GPU Frame Capture > disable ". Now I have only SKView error message hope it will be gone when I install XCode 12.
I hope it was helpful!