I figured it out, there was some tabs in my permission configuration.
You, where right. Something is messed up with my server. I tried with another protection plugin, same error.
Nothing in my error log that may point to the problem? Says something about permissions.
Also, the config file popped out of nowhere. But the error still occurs.
I don't see any configuration file, even after restarting the server :/
Also I get "An internal error occured while attempting to perform this...
The help screen really needs an overhaul.
I'd use this plugin if you could set a limit to how many protected chests a player can have.
Separate names with a comma.