Minecraft – Why does Minecraft say Internal Exception: io.nettty.handler

minecraft-java-editionminecraft-java-edition-server

I try to go on a multiplayer server and it says 

Internal Exception: io.netty.handler.codec.DecoderException:
java.lang.IndexOutOfBoundsException: readerIndex (9) + length (1) exceeds
writerIndex (9): UnpooledHeapByteBuf (ridx: 9, width: 9, cap: 9)

I use the latest update for all the servers I go on, 1.8.7 and I can go on other servers just fine. I was on the server and randomly it kicked me out saying that and I can't get back on.

Best Answer

I figured it out. I couldn't get on because I was logged into Minechat.

If you're logged into Minechat you need to make sure you disconnect before exiting out of the app, Otherwise Minecraft will think you're still logged into the server.