Debug paste link:
https://pastebin.com/Xa9neJQM
Description and relevant errors:
https://pastebin.com/8x5y7p5P
This error message appears every time a player quits. There is also a separate error that occurs when players join. Why is this happening?

I am running ProtocolLib 4.4.0 with Spigot 1.13.2.