Can't activate protected content plugin

Hi,

I can't activate this plugin. Wordpress doesn't allow it to activate. I deactivated this plugin to try membership plugin, Then I deleted membership plugin to go back to protected content. Now wordpress doesn't allow me to activate this plugin.

Support access is granted. Can some one please log into my site and see what's going on? Activate it in my 'testing' site.

Thanks!

Here are some screenshots:
http://prntscr.com/6vliry
http://prntscr.com/6vlitg