Server not crashing but I can´t enter

The Aternos forums are now deprecated

Learn more about this change here.

For help regarding Aternos, we recommend you to visit our support center.

  • I have created a server to play Minecraft with my sister and I keep getting this message when I try to enter my server: Internal Exception: io.netty.handler.codec.DecoderException: java.lang.IllegalArgumentException: Unknown recipe serializer twilightforest:transformation_powder.


    Do you guys know why?

  • Such issues usually occur if the players who try to join the server don't have the exact same collection of mods installed on their computer as the server.

    Note that also the versions of the mods must match.

    Thanks!! I'll try that!