There's a player who's ID number is 54, name is Null, and IP address is unknown... That 'user' is almost always on the server... Who, or what, is that user?
CoderMusgrave kind of has it right. These are usually caused by things that connect to my server but aren't actually Mythruna clients but they somehow leave the connection open. This is also what a player will look like who is still logging in or is in the process of connecting.