Q. Why am I receiving “Site could not be added – Bad HTTP response (403 Forbidden)” message?
There is an issue with the WordPress “Bad Behavior” plugin. You can resolve this problem by going to the Bad Behaviour settings and allowing form postings from other sites.
If you don’t have this plugin installed, the problem is that your hosting provider is blocking our IP. Please check with your hosting support if they are blacklisting ManageWP’s IP (199.187.122.66).