Hello,
i can not join official servers anymore. I get the message ‘Authentication failed‘.
I also noticed that a bazzar deal failed before.
Thanks in advance to help me and enable auth again
I fixed this by buying ingame coins. It looks like the bazar failure - when i tried to buy the war cronic chapter 3 - charged me 2 times so my coins where about -1100 (negativ). I saw this in local single player. Buying 1200 coins made my wallet positiv and then i was able to join online again.
So, i spend 3 times (~3000) ingame coins but did not get the objects from the bazar. 
… but i can play again.
If anyone else has tried this, regardless whether it worked or not - reply please.
I am still having the same issue, even bought coins, was able to get the item I wanted, validated the files twice, and it still wont let me join my friends server. Any help is welcomed