Xcode was just updated, maybe that is why the installation is not detected, even after launching and agreeing etc.
As it stands Xcode 8 is referred to as an incomplete version when linking with the newest version of studio,.
I have the same issue. We resolved by downloading latest xcode 7 and running alongside xcode 8. https://developer.apple.com/download/more/?name=Xcode
Thanks hasslunsford! How does one runs xcode 7 and xcode 8 alongside?
I ran to the same issue today. Still trying to resolve it. I have the same question. How can you run Xcode 7 along side Xcode 8?
FYI, I downgraded to XCode 7 and simulator is working again.