Microsoft recently introduced new ASP.NET Identity - replacement for old (Simple)Membership. Unfortunately, I can\'t use this new membership system in my old project because
I had the exact same error, but as it turned out I had another configuration problem in my web.config. My web.config was missing the attribute defaultLanguage="c#" in the compilation element under system.web.
In this case it will default to VB. So unless you have your Startup class written in VB you should change the default language to C#.
Not correct:
This is correct (unless you use VB):