I Can't Join My Server

The Problem is: Everything launched properly, but when i try to join my server it says that i have maximum characters bla bla bla.
But i don't think so because my name is Lixyde it has 6 characters. But in the server logs says that i have maximum 21 > 16.
21 is my number of characters, and 16 is the allowed? I don't know what that is and what that means, and i don't think is from
a plugin because i have plugins that i'm tried before and this problem never happened before.
If you want my log here it is: https://pastebin.com/ZgddeVMD
Please tell me what is this, and tell me how to fix it? Is it from Aternos? Is it from my plugins? Is it from my name? (Hm.. I don't think so)
I don't know please tell me.

Yes, The server is Cracked and i joined with cracked version.