Which module are you submitting this issue for?

Ranks

Describe the issue you are experiencing.

The plugin worked as intended, until I added commands. When someone ranks up, I add them to a group using "/manuadd {player} rank". When I use the command /rankup, I get the wanted group, but I also get a warning message(I will llink it down below.)

Describe the steps to reproduce the problem.

Add a command to a rank, and use the command /rankup.

Anything else we need to know?

The link for the log: https://pastebin.com/9H31Gt7e

I'm using spigot.

It seems like I solved this. I was using a plugin to unload and then load prison. And I think it does not like getting reloaded while the server is running.

The error you're seeing is due to Java finding that there are two class loaders loading the same class. So far, I've been unsuccessful in recreating the problem.

Is there anything unique about about your server setup?

Edit It could also be that you might have two Prison JAR files in your plugins folder.