Hi, I had the same problem, and I figured it out... The problem occurred when you use the install Xcode from external hardisk or USB just uninstall the existing Xcode, then download clean one from https://developer.apple.com/xcode/ and install it then all work fine. Hope this help you

Hi, The problem occurred when you use the install Xcode from external hardisk or USB just uninstall the existing Xcode, then download clean one from https://developer.apple.com/xcode/ Hope this help you