Question: I have a QuestionControl.ascx and a QuestionControl.ascx.cs code behind file I copied to a new project. When I build the project any references in the code behind file to controls declared in the ascx gives me this error:

> 
> 'QuestionControl' does not contain a
>  definition for 'rdbtnlstQuestion1' and
>  no extension method
>  'rdbtnlstQuestion1' accepting a first
>  argument of type 'QuestionControl'
>  could be found (are you missing a
>  using directive or an assembly
>  reference?)
> 
> 
> 

This is at the top of my \*.ascx:

```
<%@ Control Language="C#" AutoEventWireup="true" CodeFile="QuestionControl.ascx.cs" Inherits="QuestionControl" %>

```

I've also tried CodeBehind:

```
<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="QuestionControl.ascx.cs" Inherits="QuestionControl" %>

```

This is the top of my class in the codebehind file, it is not contained in a namespace:

```
public partial class QuestionControl : System.Web.UI.UserControl
{

```

Answer: 
In VS2017 there is no option 'Convert to Web Application' in the context menu of the .ascx file. Instead you need to select to .ascx file then click on 'Project' in the upper menu and select 'Convert to Web Application' (which is all the way down in the Project menu.
What worked form me was listed on another SO answer and I can't find it so I'm repeating it here.

Try deleting your "ReflectedSchemas" folder in 

C:\Users\YOURUSENAME\AppData\Roaming\Microsoft\VisualStudio\15.0\_079f391b\ReflectedSchemas

This worked for me. Sometimes I get the "unrecognized" errors, and I delete this folder again. Many thanks to the OP. Been driving me crazy for years. Now I have no "squiggles" in the HTML and no "red bars" in the code behind (aspx.cs)