Thanks for taking the time to open a bug report!

Describe the bug
The command assigned to the item does not work

To Reproduce
Steps to reproduce the behavior:

when I right click on the item

Expected behavior
it does not work

Screenshots
https://imgur.com/A8s9PDL

Pastebin
Even if it is not related to the problem, please include ALL configuration files in separate Pastebin.com links as well as any related error codes from the console window.

Please complete the following information:

• Resource Version: v5.2.1-RELEASE-b678
• Server Version: 1.8

Additional context
no

So I would start by updating ItemJoin as you are using an outdated release version. The latest release is v5.2.2 which removes the use of Hikari as displayed in your error message.

However, I would suggest the latest v5.2.3 snapshot as it is more stable than the current v5.2.2 release.

Link; https://ci.craftationgaming.com/job/ItemJoin/754/
Remember to remove your old ItemJoin.jar file

Let me know!~

This is likely now fixed in the latest release, I would suggest starting there. I am going to mark this as resolved due to inactivity, please feel free to reach out if you still need help.

You can now download it here; https://www.spigotmc.org/resources/itemjoin.12661/download?version=431799