title: VSIXManifest cannot be loaded
body: <p>i've installed the Microsoft Visual Studio SDK to develop extensions for Visual Studio. But even when i create a simple example without any changes from the templates, Visual Studio refuses to fully compile the extension.</p>
  
  <pre>
  1>------ Rebuild All started: Project: VSPackage1, Configuration: Debug Any CPU ------
  1>  VSPackage1 -> 
  1>  VSPackage1 -> 
  1>  VSPackage1 -> o:\daten\visual studio 2012\Projects\VSPackage1\VSPackage1\bin\Debug\VSPackage1.dll
  1>  Creating intermediate PkgDef file.
  1>C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v11.0\VSSDK\Microsoft.VsSDK.targets(75,5): error : VSIXManifest cannot be loaded. Ensure VSIXManifest is a valid XML file.
  2>------ Rebuild All started: Project: VSPackage1_IntegrationTests, Configuration: Debug Any CPU ------
  2>  VSPackage1_IntegrationTests -> o:\daten\visual studio 2012\Projects\VSPackage1\VSPackage1\VSPackage1_IntegrationTests\bin\Debug\VSPackage1_IntegrationTests.dll
  ========== Rebuild All: 1 succeeded, 1 failed, 0 skipped ==========
  
  Projects build report:
    Status    | Project [Config|platform]
   -----------|---------------------------------------------------------------------------------------------------
    Failed    | VSPackage1\VSPackage1.csproj [Debug|Any CPU]
    Succeeded | VSPackage1\VSPackage1_IntegrationTests\VSPackage1_IntegrationTests.csproj [Debug|Any CPU]
  
  Time Elapsed 00:00:02.56
  </pre>
  
  <p>I did not change anything else. Any suggestions?</p>