Hi im having the same problem, reached level 6 and i cant progress any further. Ive tried every possible combination, even tried deleting the game and downloading back but its still the same. Help??
I have tried that all ready but it doesn't work. I have even tried names I would not use, random letters and random words. It just doesn't seem to work.
For some players typing more than 22 random letters has solved this problem.
Another option is to delete the progress and restart the game from level 1.
There's an open thread in Bug Reports collecting info from all the users that have this issue, so I'd recommend adding your details to that! @EA_DragonsEye has requested all players experiencing this glitch to DM them your player ID and a brief explanation of what you're experiencing so that they can follow up.
It seems to be impacting quite a significant proportion of players so hopefully by the next update it will be resolved.
This thread is now locked as it is from 2018 and the issue was then solved.
Players experiencing this issue now in July 2021, please read and comment on the new thread [Open] - Player Name Format not accepted.
Thanks @FinnKimbrel for your help