title: Visual Studio Design View - form is blank
body: <p>I have a C# project with two forms. All compiles well. When I run the project, all forms are drawn as they are expected to. </p>
  
  <p>A couple of days back, the DesignView of <strong>all</strong> forms started to shown nothing but a blank form, like the one you get in a new Windows.Forms project. </p>
  
  <p>I went through several questions on SO with a similar problem, here are the comments to those questions:</p>
  
  <ol>
  <li>there are no 3rd party libraries that my project uses (apart from htmlAgilityPack, which does not cause this problem in other Windows.Forms C# projects)</li>
  <li>I have checked that the InitializeComponent function is only once in the project for each form</li>
  <li>When I create a new Project and add an existing form (i.e. one of my problematic project forms), the Design Viewer works as expected - hence I suspect that the .cs, .Designer.cs and .resx files of my forms are OK. </li>
  </ol>
  
  <p>Is there something I could have messed up in the project settings or somewhere else?</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>The third point above is misleading - I tried creating a new project for the second form as well and there the problem persist. The minimal amount of source code that shows the problem is to to be found <a href="https://www.dropbox.com/s/l410twqwzzv5kxd/mainForm.rar?dl=0" rel="noreferrer">here</a>.</p>