title: Xamarin Studio/Visual Studio Broken - The target "Build" does not exist in the project. (MSB4057)
body: <p>I'm starting out with Xamarin Studio after working with Visual Studio (2012 last) for a good few years. However someone through importing projects, and starting new Android projects I've managed to break Xamarin Studio.  Now when starting a new project I get the following error;</p>
  
  <pre><code>The target "Build" does not exist in the project. (MSB4057)
  </code></pre>
  
  <p>The steps;</p>
  
  <p><img src="https://i.stack.imgur.com/CriUv.png" alt="Starting a new project"></p>
  
  <p><img src="https://i.stack.imgur.com/zLOI2.png" alt="Build result"></p>
  
  <p>I've tried to repair my installation, but this made no difference. I've tried doing a reinstall but this made no difference.  Other than a complete uninstall and reinstall what options do I have?</p>
  
  <p>I'm using Xamarin Studio 4.2.2, and can confirm I now have the same problem in Visual Studio 2012.  Although I can manually build projects using MSBuild.exe, but other than that both IDEs are broken.</p>