If you are observing the Account Authentication Failure. <unlocalized "loc_error_banned_with_expire_time": string not found> error on attempting to load in to Darktide, it means your account has been banned.
The error is not adequately localised at this time, which is why it contains exposed code.
I get an error whenever I try and launch the game saying Backend Error or Failed to load player profile preventing me from loading into the game.
Edit: If I’ve been banned I would really like to know why because I can’t think of anything I could possibly have done to warrant a ban.