Describe the bug
When i join the server (spigot version 1.16.2 but also on 1.16.3 this error occurs about PacketDataSerializer)
It's not really making the server crash or whatever, but it's really annoying on console.

To Reproduce
Steps to reproduce the behavior:

1. Start the server.
2. Join the server.
3. See error on console. https://paste.helpch.at/zeyexuqama.md
   This error happens from 1.16.2 and higher. Also happens with dev build from jenkins.

Expected behavior
No error.

Version Info
https://paste.helpch.at/yuhetuxilo.cs