The plugin works fine, but why can't I uninstall it? help please.
I removed the jar file

Did you stop the server before removing the jar file?

I first removed the jar and then restarted

Did you:

1. Stop the server
2. Remove the Jar
3. Restart the server?

Or did you do something even slightly different?

1. Remove the Jar
2. Stop the server
   3 .Start the server

Try what he said

If I have already deleted the jar file

Try downloading OCM again and take it out the method he told you to do.

Thanks

If that still doesn't work follow the instructions here.