title: Clean Solution causes reference errors
body: <p>I have tried to search through previously asked questions, but it is difficult to sift through them because it seems 99% refers to reference problems <em>after a build</em>, whereas my problem is references issues <em>after a clean</em>.</p>
  
  <p>The problem is as follows, I am reviving an old project -which I've never worked on previously unfortunately- and everything compiles and works fine when I build the solution.</p>
  
  <p>When I do a Clean Solution though, I get reference errors for one project. The project in question is a Visual Basic web service project. It has a reference to two other projects (which are C#) and when I look at the Project Properties, in the References pane I see that the Path used for the reference is SolutionFolder\Project\bin\Debug\Projectname.dll. </p>
  
  <p>So whenever I clean my solution the bin\Debug is emptied and the reference is missing. Does this mean the reference is setup wrongly?</p>
  
  <p>I understand from researching the issue that Project References work differently for VB projects, but I find it weird that a combination of C# and VB projects would give reference errors the moment you clean the solution.</p>
  
  <p>Can anyone help me / explain why this happens?</p>
  
  <hr/>
  
  <p>Okay, I've created steps to recreate the issue. It works as follows:</p>
  
  <p>Visual Studio -> New Project -> Visual Basic WCF Service Application</p>
  
  <p>Solution -> Add -> New Project -> C# Class Library</p>
  
  <p>In the class library add the following function</p>
  
  <pre><code>namespace ClassLibrary1
  {
      public class Class1
      {
          public static int Foo()
          {
              return 1;
          }
      }
  }
  </code></pre>
  
  <p>Visual Basic WCF Project -> Add -> Reference -> C# ClassLibrary (from the Solution Project)</p>
  
  <p>Build Solution</p>
  
  <p>In the Service I change the GetData function as follows:</p>
  
  <pre><code>Public Function GetData(ByVal value As Integer) As String Implements IService1.GetData
      Dim foo = ClassLibrary1.Class1.Foo
  
      Return String.Format("You entered: {0}", value)
  End Function
  </code></pre>
  
  <p>Build Solution</p>
  
  <p>Now Clean Solution.</p>
  
  <p>Visual Studio now tells me I have reference errors.</p>
  
  <p>Build again.</p>
  
  <p>Errors gone.</p>