Asp.Net Running a content page using master page error > TemplateContainer(typeof(MySite.MasterPage))

Question

I created an empty asp.net web application > .Net 4.6.2 in VS 2015
I added a simple master page & a simple content page on this project.
When i open content page in browser i get the error below :

Line 174: [TemplateContainer(typeof(Panel.Site1))]

What this error mean & how can i fix it?

Answer 1

Name of your project or namespaces conflicting with ASP.NET form authentification class name: System.Web.Security.FormsAuthentication. According to me you are missing namespace name or any required reference.