title: "Has invalid child element" warnings in Microsoft.Common.Targets while building
body: <p>In my VS2010, when I build my solution, I have over 100 warnings in the file <strong>Microsoft.Common.Targets</strong>. When I try to build, publish or run my programs, I get just the warnings, but the moment I double click it to get more info, the Microsoft.Common.Targets pops up and then I get all on the warnings.</p>
  
  <p>This file Microsoft.Common.Targets is part of the .net framework and has the MSBuild in-built targets, etc. And it has the approperiate schema associated in the properties window.</p>
  
  <p>Some example warnings (2 out of 100) :</p>
  
  <pre><code>Warning    2    The element 'PropertyGroup' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003' has invalid child element 'CustomBeforeMicrosoftCommonTargets' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003'. List of possible elements expected: 'Property' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003'.    C:\WINDOWS\Microsoft.NET\Framework\v3.5\Microsoft.Common.targets    22    10    Miscellaneous Files
  Warning    3    The element 'PropertyGroup' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003' has invalid child element '_OriginalConfiguration' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003'. List of possible elements expected: 'Property' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003'.    C:\WINDOWS\Microsoft.NET\Framework\v3.5\Microsoft.Common.targets    60    10    Miscellaneous Files
  </code></pre>
  
  <p>Why is this file suddenly in my editor, when it is not part of my project, and how to tell visual studio to ignore this framework file while building.</p>