The connection to the server will get lost because of an "Internal Exception" when you are trying to connect and you are in the end.
When entering the end the first time there are no blocks around (like when nether is disabled on the server). Trying to reconnect will bring up the error.
Tested on different servers with new and old worlds. No Problems in Singleplayer.

Error Message: Internal Exception: io.netty.handler.codec.DecoderException: java.io.IOException: Packet 0/38 (jn) was larger than I expected, found 45056 bytes extra whilst reading packet 38