title: Get exception after applying Visual Studio 2015 Update 2
body: <p>Get the following exception after update Visual Studio 2015 with Update 2 today. Now I can't connect to TFS. </p>
  
  <p><em>Method not found: 'System.Collections.Generic.IEnumerable<code>1&lt;Microsoft.TeamFoundation.Framework.Common.EnumeratedSparseTreeNode</code>1> Microsoft.TeamFoundation.Framework.Common.SparseTree`1.EnumParents(System.String, Microsoft.TeamFoundation.Framework.Common.EnumParentsOptions)'.</em></p>
  
  <p>Tried to register <em>Microsoft.TeamFoundation.Common.dll</em> to GAC from path '<em>C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\lfiy4m2k.1dh</em>'. Still not work. (I checked that <em>Microsoft.TeamFoundation.Common.dll</em> with telerik JustDecompile, and it already has the method EnumParents.)</p>
  
  <p>Thank you for your help.</p>
  
  <p>Update: 
  Attach the image:
  <a href="https://i.stack.imgur.com/FcprF.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FcprF.jpg" alt="enter image description here"></a></p>
  
  <p>Update: 
  In short, in the end I've restored the system to an old one. That one has Visual studio 2015 with Update 1 installed. I may not update Visual studio 2015 with Update 2 currently.</p>
  
  <hr>
  
  <p>Things I've tried:</p>
  
  <ol>
  <li><p>Register Microsoft.TeamFoundation.Common.dll(14.95.25118.0) to GAC. Not working. This used to save my life before.
  gacutil -u Microsoft.TeamFoundation.Common.dll first. 
  gacutil -i Microsoft.TeamFoundation.Common.dll later.</p></li>
  <li><p>Run devenv /log. ActivityLog.xml shows nothing help. Just tells that TeamFoundation.vsix is duplicate with something other. </p>
  
  <p>One extension is from a path like C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\sgafzsci.zbq. 
  The other one is from C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\CommonExtensions\Microsoft\TeamFoundation\Team Explorer.</p></li>
  <li><p>Try devenv /resetuserdata. </p></li>
  <li><p>Clear contents in folder Component Model Cache.</p></li>
  <li><p>Repair Visual Studio 2015 </p></li>
  <li><p>Reinstall Visual Studio 2015 Update 2. </p>
  
  <p>*Tried 5 &amp; 6 several times.</p></li>
  <li><p>Uninstall VS 2015 from control panel -> Program Features.</p></li>
  <li><p>Run vs_enterprise.exe /uninstall /force from the programdata/package/{guid}/</p>
  
  <p>Delete all data in C:\Program Files (x86)\Microsoft Visual Studio 14.0,
  C:\Users\UserName\AppData\Roaming\Microsoft\VisualStudio\14.0, 
  C:\Users\UserName\AppData\Roaming\Microsoft\VisualStudio\14.0Exp,
  C:\Users\UserName\AppData\Local\Microsoft\VisualStudio ( all data in this folder except the 10.0),
  C:\Users\UserName\AppData\Local\Microsoft\Team Foundation,</p></li>
  <li><p>Install an Visual Studio 2015 with Update 2 in offline mode. 
  Still not working at this time.</p></li>
  <li><p>Uninstall the vs 2015 with update 2 with command line /uninstall /force</p>
  
  <p>This time, I can't uninstall the updates from Windows Update now.... I assume that the environment is totally messed up. To tell the truth, I didn't check the windows update before this step. I checked this time, cause when trying to install visual studio 2015 without updates in offline mode, it tells me that the update 2 is already installed in the computer.</p></li>
  <li><p>restore the system to an old version. </p>
  
  <p>I've experienced another April fool's day. </p>
  
  <p>PS: I've to mention that I use ProcessExplorer and search Microsoft.TeamFoundation.Common.dll, vshub.exe and denenv.exe both are having the latest Common.dll loaded.  Also, after step 9, I search in C: driver list all the Microsoft.TeamFoundation.Common.dll files. Only the one from TestAgent is the old version. All else are the latest.</p>
  
  <p>PS: 1. run tf get still gives me the same issue. </p>
  
  <ol start="2">
  <li>Install VS 2015 TFS PowerTools and use get from that gives me the same issue.</li>
  <li>Try C# code by calling the function <a href="https://msdn.microsoft.com/en-us/library/bb139264(v=vs.120).aspx" rel="nofollow noreferrer">Workspace.Get()</a> gives me the same issue. Reference to old version of TFS related dlls still gives me the same issue. I don't understand why and didn't look into it deep.</li>
  </ol></li>
  </ol>
  
  <p>Updated: </p>
  
  <p>Reinstall the OS at end. This time, I installed Visual Studio 2015 enterprise version with Update 2. It works good.</p>