Title says it all. As soon as Forms is up and running, all possible access to the site is lost. I can set access to anonymous (via powershell only) and I get access back. After turning anonymous back off, access is lost in the next hour or so again. To be clear, neither forms or claims works after forms is set up. My site collection admin has no access to his site. Also I can access CA, but as soon as a click something I am prompted (and the prompt is broken).
I'm using this method. I've now built this server from the ground up twice. Help!
http://blogs.technet.com/b/ptsblog/archive/2013/09/20/configuring-sharepoint-2013-forms-based-authentication-with-sqlmembershipprovider.aspx