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?