This is a simple release which adds support for Citizens NPCs. Previous to this update, LevelledMobs spat out errors when Citizens NPCs spawned in. That's fixed now.
File Modifications:
None, drag and drop this version in. Too easy.
Testing Status:
This release wasn't tested, but the change is so minuscule that I am 99% sure it will work perfectly.
Changelog:
Fix | Added check to 'isLevellable' to make sure that the entity in question is not an NPC. Thanks to @LuisElGamer123 for reporting this issue to me.