I get the following error on the event viewer when trying to log on a Sharepoint website with forms-based authentication (FBA):
The http request is unauthorized with client authentication scheme 'negotiate'. The authentication header received from the server was ''.
I've configured FBA using this tutorial (http://blogs.visigo.com/chriscoulson/configuring-forms-based-authentication-in-sharepoint-2013-part-1-creating-the-membership-database/)
On IIS, the website's authentication is configured to only use forms-based authentitcation.
Central Admin is configured to use Windows Authentication and ASP.NET Impersonation.
Security Token Service is configured to only use forms-based authentitcation.