title: (ASP.NET) Project file must include 'WindowsBase, PresentationCore, PresentationFramework'
body: <p>I'm seeing an inscrutable compile error in my ASP.NET application.</p>
  
  <blockquote>
    <p>Project file must include the .NET Framework assembly 'WindowsBase, PresentationCore, PresentationFramework' in the reference list</p>
  </blockquote>
  
  <p>That's the WPF assembly.  My project is ASP.NET.  Has anyone ever encountered this before?</p>
  
  <p>Even stranger, the project was compiling before I started messing around with my .resx files due to a different issue.  Then suddenly this nonsensical error appeared.</p>