For some time now my console has been getting spammed with the following stack traces.
https://pastebin.com/kKdLUD06
This has actually been going on for several months but I was busy with other things and ignored it because it would only start occasionally, then stop after 5-10 minutes. Now it's non-stop.
Any help with this would be greatly appreciated.

FactionChat v1.10.4
MassiveCore v2.10.0
paper 1.11.2 # 1104

are you using McMMO? If so what version?

Yes, version 1.5.07-SNAPSHOT

Here are some more examples in case it's helpful. Btw, this log was taken while mcmmo was not loaded.
Factions Chat version: 1.10.5
McMMO version: 1.5.08

FCExample.zip

Thanks for the extra info. I'll be updating it very soon

okay the latest version of McMMO should have that class... regardless I've made some changes so can't fail