IP blocker does not seem to work with WordPress 4.1. Since upgrading to 4.1 IP blocker will not work.
When I look at the plugin installer it says IP Blocker has not been tested with the WP version 4.1. Do you have any intention of updating the plugin? I found it until recently very good for blocking foreign countries notorious for hacking.. I have since had to delete it.
Please fix so I can use again.