sorry, I can't activate or deactivate the waf at this place. There is no switch like in the official release.
WAF = Web Application Firewall (Webserver Protection -> Web Application Firewall)
Ok, I was little bit unclear. I meant, if you have under "Webserver Protection" one or more Virtual Webservers created and at least one of them active, you cannot activate transparent SSO.
If you haven't a virtual webserver running, this message shouldn't appear.