With Xcode 8 beta 2, App Submission causes ERROR ITMS-90534.
Full Message is:
ERROR ITMS-90534: "Invalid Toolchain. New apps and app updates must be built with the public (GM) versions of Xcode 6 or later, OS X, and iOS SDK or later. Don't submit apps built with beta software including beta OS X builds."
PS. I don't use macOS beta.
I think that this is a temporary issue on iTunesConnect side. Any idea?
I found TestFlight release note, It says beta 2 is not supported by test flight and iTunesConnect yet.
For now, we should use Xcode8 beta1 to use testflight.
https://developer.apple.com/testflight/release-notes/
PS. iMessage App can't be submitted using beta1 since testflight doesn't support iMessage App yet.