Ive been informed by my staff on the server that there are bugs in your plugin mainly

1. Quests can bug if people log out after accepting the quest
2. Handing in items to an npc does not give completion rewards or credit
   is there a way to fix this
   using minecraft 1.11

NPCrightclickEvent error is resolved (using # 118 dev build If you run 1.11 Spigot server)