Java Error: biz cannot be cast to fv

So I have added one of my servers to the Bungee network and I have set up Screens for both of them, edited the config files to match what the instructions say and started them the right way. I'm am trying to connect through the bungee ip but in the server console it says I failed to connect. The server is the default server and the message I get when trying to connect is:
Internal Exception: Java.lang.ClassCastException: biz cannot be cast to fv
Any ideas?
Thanks,
Phoenix