Kedikans

I created a modded fabric server on minehut, and i can join but my friend gets an error message saying: "Internal Expedition: io.netty.handler.codec.DecoderException: java.io.IOException: Packet 0/56 (class_2708) was larger than I expected, found 4 bytes extra whilst reading packet 56" , joins then right after leave. He has downloaded the mods on the server exactly like me, so please help me undersstand and fix the problem so we can play again.