Cant get into server - "cant make a new character error"

Sometimes when i go to log into my server (Kazeros - South America) it get that error. I have 1 main and 3 alts. Problem started occurring after I let my little sister make a character (3rd alt) on the server. Just wanted to let u guys know about this problem before it permanently locks me out. Just reached tier 2 lol. Kinda don’t want that to happen.

It fixes itself if i restart.

edit: I was there for early access