when i go on a server it says 'bad packet' even though im on the full edition

I've been playing minecraft for a couple of weeks now and I have downloaded some servers.
I use this one (fate.playmc.net) a lot now and recently its been popping up with
internet.exception:io.netty.handler.codec.DecoderException:java.io.IOException:bad packet id 70.
it is really annoying and I delete the server and re-do it again it saying that again.
PLEASE HELP!!!!!