Same problem here. Mac Pro 2013, OS X 10.11.6, Xcode 8.0, UE4.13.1 from the launcher.
I have tried the “rename and put in this folder and select it” workaround and the “manually import it and select it” work around. Neither changed anything. 
Same problem here. Mac Pro 2013, OS X 10.11.6, Xcode 8.0, UE4.13.1 from the launcher.
I have tried the “rename and put in this folder and select it” workaround and the “manually import it and select it” work around. Neither changed anything.