title: Codebehind file doesn't recognize aspx-controls
body: <p>I was given a webproject written with aspx/c#. When I loaded it into Visual Studio 2010, I got many error telling me that some controls in the code-behind files do not exist in the current context.</p>
  
  <p>I checked for the common pitfalls, like wrong code-behind file name, missing <code>runat</code>-attribute, restart VS, reload project, yet nothing resolves the error.</p>
  
  <p>What else can I do to check where the problem is?</p>