I have only errors in my console, thats all.

Config: https://pastebin.com/fXeen0F5
Items: https://pastebin.com/vT7eYzQB
Errors: https://pastebin.com/D8zFsfaF
Spigot 1.11.2
ItemJoin version 4.8-SNAPSHOT

Thanks for the report, I am looking into this now.
However, I have a funny feeling that (THIS IS NOT AN ISSUE TO DO WITH PER WORLD PLUGINS) is a lie lol.

Okay, so I have done some extensive testing into this.
To start things off; you are using PWP from https://dev.bukkit.org/projects/perworldplugins correct?

PwP from that link does not work for 1.11.2. It causes issues with most plugins and even prevents me from typing /reload or /stop in console.

My assumption is that you are using that one.

Please let me know!

I am going to close this issue since its been inactive for a while, but if you come across it and you are still having issues please feel free to re-open.