ERROR: "JoinRoom failed. Client is on MasterServer"

Options
Hi.
I recently updated to the latest PUN Version on the Unity Asset Store.
Now i get the error Msg "JoinRoom failed. Client is on MasterServer (must be Master Server for matchmaking)but not ready for operations (State: Joining)." when i joining to a room.
But the thing is, it joins the room and i can also play normaly my game.

Any ideas what cause the error msg?

(sorry for my english ;) )