My friend can't log into his main character

My friend can't log into his main character but can create a new one. Since the second update, he's been experiencing crashes. After reinstalling the game, he was able to continue playing, but today, when he launched the game, it started crashing instantly, and he couldn't get in at all. Reinstalling or changing the settings doesn't help, making it impossible for us to play together.

And now his character's name has another friend's character's name appended to it.Even if I edit the notes, the extra name won't disappear.