I can't access my website after installed 6 SCAM security

I just installed your plugin 6 SCAM security on my wordpress site and after the activation of this plugin i have an error:
“The website encountered an error while retrieving http://new.radiogmusic.com/wp-admin/plugins.php. It may be down for maintenance or configured incorrectly.”

“HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.”

http://wordpress.org/extend/plugins/6scan-protection/