Hi, Claude31, Thank you very much. I finally discovered that my iPhone is running iOS 15, which is not compatible with Xcode 11. Thanks again for your help.

The same problem - I have macbook pro 2012(16 GB RAM + 512 SSD + 750 Sata drive) - and now my macbook is ruined without update xCode, I can't develop by using it=( but it's powerful enough for develop 3D games etc, it's so awful. The Book Develop in Swift Fundamentals with XCode 11 is not fully compatible with XCode 11.7 and when I run XCode 12, it shows the error message that you cannot use XCode 12 with Mac OS 10.15 you require a Mac OS 11. Can someone suggest some working solution