My friend is kicked from all aternos servers

My friend cannot stay on any Aternos server for long, not even her own. When us and other friends try to go on any Aternos server, it will say "MaggieMage joined the game" but she can't talk or move, and about 20 to 30 seconds later it kicks her. I have changed the software from vanilla to spigot to bukkit several times, and bukkit lets her temporarily play, but if she disconnects or is afk kicked, she can't come on again. I think something might be wrong with her Java, so I'll have to look into that later. But right now, we need help!

She gets different ones every time, but she won't tell me what they are (she's too lazy to).

Okay, I'll get her to tell me the error messages.

She says some of them are "gibberish" which I guess is command data, some of them are "remote host", and that's all she can remember.