I get some error messages in logs
[User Defaults] Failed to write value for key GameId in CFPrefsPlistSource<0x1740faf00> (Domain: xxx.xxxxxx, User
Lot of people are finding this issue on Xcode 8.
"As crazy as it sounds try rebooting phone and host, sometimes Xcode can get stuck for sum reason only restart helps.
build with Xcode 8.1 Beta and you will see the same warning, but you will also get the value. "
reference : https://forums.developer.apple.com/thread/51348