Connection Lost: internal exception java.lang.nullpointerexception cannot invoke net.minecraft.nbt.CompoundTag.m_128459_(String)

[JJJaming]

Hi! I am trying to run a custom forge modpack on 1.20.1 and the server appears to start up normally but whenever someone tries to join they get this error:
Connection Lost: internal exception java.lang.nullpointerexception cannot invoke net.minecraft.nbt.CompoundTag.m_128459_(String) because nbt is null
I just want to make sure it isn't a server sided issue and maybe get some advice if it is a client issue. Thanks! The server is run off of Exaroton/Aternos

Client Log https://mclo.gs/o6rIGTd

Server Log: https://mclo.gs/IBHbX7O

[CailynBrandt]

Try loading the world on a single server and check if there are any corrupted data or chunks. Sometimes corrupted data can cause similar errors when players connect.
Or you can try using a different hosting: if you're using Exaroton or Aternos, try changing the server hosting temporarily to see if the problem persists on a different hosting.