Getting this error when a player joins. Using 5.4.0 and Spigot 1.8.3

http://pastebin.com/11MUupJ3

Are you running behind bungeecord?

No I am using Spigot 1.8.3 like I said. I typed /version at the end of this log http://pastebin.com/GCR38mhB

Found the issue. Had to do something with my messages file.

EDIT: The issue is with MaxOnlinePerIP. If it is set to any number that error happens.