Make sure you've done the following:

• [*] You're using the latest build for your server version
• [*] This isn't fixed in a recent development build
• [unsure] This isn't an issue caused by another plugin
• [*] You've checked for duplicate issues
• [*] You didn't use /reload

Dump link:

https://gist.github.com/Big-Guns/1b4f05ad6ac6ade628a13a817a986bdb

Description and relevant errors:
Started throwing the following error the other day, not sure why.
https://gist.github.com/Big-Guns/85fbdaee8008f4d14bc568742525afea

Plugins list: https://i.imgur.com/6sYhvjR.png

Same error for me