I am trying to release an app from Xcode but as soon as I try uploading to the app store or exporting in any fashion, once it checks for signing from iTunes Connect, I receive the error
Your session has expired. Please log in.
The session of one of my accounts (not even the one I was trying to use) had its session expired. This seems to be new. I just had to re-sign in to the errant account in Xcode > Preferences > Accounts.