http://stackoverflow.com/questions/33291394/xcode-7-1-not-authorized-to-use-this-service-error
You are not authorized to use this service
Xcode 7.1 ships with App Loader 3.3
I tried removing and adding my iTunes account, restarting Xcode, checking the provisioning profiles.
A couple of reboots later and the App loader finally worked.
Tools
https://developer.apple.com/downloads/?name=for%20Xcode
https://itunespartner.apple.com/en/apps/tools
https://itunesconnect.apple.com/apploader/ApplicationLoader_3.0.dmg
https://itunesconnect.apple.com/apploader/ApplicationLoader_3.1.dmg
