Console error logging in

[00:58:44 INFO]: [VanishNoPacket] BlackScorpion disappeared.
[00:58:44 INFO]: BlackScorpion[/xx.xx.xx.xx:49922] logged in with entity id 59 at ([plotworld] 0.5089959323058356, 64.5, 0.7443002928428835)
[00:58:45 INFO]: BlackScorpion lost connection: Internal Exception: io.netty.handler.codec.DecoderException: java.lang.RuntimeException: An internal error occured.