Unable to upload app to iTunes Connect - iTunes Store operation failed. Authentication timeout

This usually happens to me when the phone is connected while uploading the archive, and removing the phone so far has been solving the issue for me.

My solution was to install Application Loader. At first it seemed like it's stuck as well, but after about 10 minutes it started uploading.

I solved this issue.

There is a checkbox "include bitcode" at the bottom of the Summary screen (when you validate Archive) or Send XXX to Apple screen (when you upload to App Store) where the Organizer show the Binary and Entitlements together with Provisioning Profile. In XCode 7 it is checked by default. I unchecked it and re-run Validation - worked fine. As soon as checked the checkbox back on, it started failing with same error.

I have also unchecked the other checkbox on the same screen - symbolis upload.

Successfully uploaded the binary using the Organizr just now.