Connection problems

Outdated client / Outdated server

What the log looks like

outdated (?:client|server)!?
io\.netty\.handler\.codec\.decoderexception
internal exception: *io\.netty

How to fix it

  1. The client and the server are on different Minecraft versions
  2. A netty DecoderException on a modded server usually means mismatched mod lists
SeverityBreaks something
CategoryConnection problems

Check your own log

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