On December 23rd, 2018, I was about to switch between characters when, after pressing the "Quit" button in options, a notification reading "Invalid Username" appeared on my screen, after which i was disconnected from the game. I was able to log back into my account, however the "Invalid Username" notification worries me as it has never happened before. Any insight as to what may be the cause of this?
If you have let your Title Screen still for a few hours (As in the place where you log into your account) and then click Play a few hours later, that can happen, or if you let your wizard spin all night and switched characters, this can happen. It happens to me all the time, so no worries!