I uninstalled 15.1 and installed 15.0 from here https://developer.apple.com/xcode/resources/ and i was able to successfully upload again. Took me 5 mins, would recommend if you need to upload apps today
cps800
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Last seen
User for
Post
Replies
Boosts
Views
Activity
Same issue with 15.1, literally submitted multiple apps two days ago no issues but now since yesterday it shows this