EssentialsX version (/essentials): 2.0.1-b488

Server software (/version): 1.12.2

Server (logs/latest.log): https://gist.github.com/KillerOfPie/3fdc662dda648319e233b6b1664c31a4

EssentialsX config (if applicable): n/a

Seems to appear when players use a rocket while flying, don't know if there are any other times. Also do believe that they removed the hashset method which would cause the nosuchmethoderror.

This has already been fixed. Update EssentialsX to the latest version.