My friend was able to join my server there is a couple of days but now he can't join at all. And when you are near of him when he crashes, he makes you crash too. I'm on a modded server in 1.16.5 with Forge 36.1.0.
The error message is :
Internal Exception: io.netty.handler.codec.DecoderException: java.lang.RuntimeException: Tried to read NBT tag that was too big; tried to allocate: 2097166bytes where max allowed: 2097152