Weird Error on Visual Studio - "you could use the navigation bar to switch context"

Question

I have been trying to link a a web form to be a able to access a variable in the master page. I did this before it worked. But now when I do it I get an error.

The code in Site.Master

<%@ Master Language="C#" AutoEventWireup="true" CodeFile="Site.master.cs" Inherits="Site" %>

The code in Site.Master.cs

public partial class Site : System.Web.UI.MasterPage
{
    public string hi = "";

    protected void Page_Load(object sender, EventArgs e)
    {

    }
}

The code in WebForm1.aspx:

<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="WebForm1.aspx.cs" Inherits="WebForm1" %>
<%@ MasterType VirtualPath="~/Site.master" %>

The Code in WebForm1.aspx.cs

public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
     {
         Master.hi="new"
     }
}

When I hover over the hi, I get this message

Error in Visual Studio - "You can use navigation bar to switch contexts

Here is another image Screenshot

If you guys could help me it will really be great

Answer 1

I had this same problem in an MVC application so the WebForm-CodeFile-CodeBehind suggestion didn't really apply.

However, I realized the new classes that I created had their "Build Action" set to "Content". Once I changed this to "Compile", everything started working again.

Answer 2

In your WebForm1.aspx, try changing CodeFile to CodeBehind. That's what worked for me.