error server

When I kill the first boss to go to the first city, I get an error, "Exception: Unknown object type serialized by server." What do I do? I deleted the first character thinking it was an item I picked up and it gave me a bug, but when I killed the boss again on the second character, I got the same error.

I'm having the same issue. Was moving stash tabs around and got the error message and got booted. got this error message when i tried logging back in so i deleted character and restarted but once i get to the encampment i get kicked with this message.