internal exception io.netty.handler.codec.decoderexception.unknown serializer type 19

[Baas10]

Can't deal with the bug internal exception io.netty.handler.codec.decoderexception.unknown serializer type 19. It appears when I try to enter to an Aternos server. I have tried changing de Firewall settings, but it doesn't work. Help please! I wanna play

Edited August 27, 2022 by Baas10

[Luis_ST]

Please add -Dforge.logging.mojang.level=debug to the JVM arguments of your Launcher.
Launch the game and produce the error, then post debug.log (client) from the logs folder.

Please also provide the server debug.log.