Unable to create team proejct from VS 2013.4

I just saw this exact problem (TFS 2013 Update 4 and Visual Studio 2013 Update 4). I found the solution posted here on the Microsoft Connect site solved the problem. In short, uninstalling some assemblies that were mistakenly installed got everything working again.

1. Close all instances on Visual Studio and Microsoft Test Manager
2. Open Visual Studio command prompt in admin mode.
3. Perform the following steps:
   ngen uninstall Microsoft.TeamFoundation.TestManagement.Client
   ngen uninstall Microsoft.TeamFoundation.TestManagement.Common

The working folder … is already in use by the workspace … on computer … In Visual Studio 2013

https://www.roelvanlisdonk.nl/2014/03/25/solving-the-working-folder-is-already-in-use-by-the-workspace-on-computer-in-visual-studio-2013/

C:\program files (x86)\Microsoft Visual Studio 12.0\Common7\IDE> tf  workspace /delete /server:http://5vvd8r1-tfs:8080/tfs\portal 4NTK622;hi\acsyssvc

When mapping a collection to a local folder in Microsoft Visual Studio 2013, I was getting the error:

The working folder … is already in use by the workspace … on computer …

To solve this problem I had to delete the workspace:

1. Close Microsoft Visual Studio 2013.
2. Open en command prompt in Administrator mode.
3. cd "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE"
4. tf workspace /delete /server:http://1.1.1.1:8080/tfs/MyCollection MyComputerName;MyDomain\MyUserName
5. Open Microsoft Visual Studio 2013. Mapping to local folder should now work.

For more information:

http://blogs.msdn.com/b/rob/archive/2012/10/13/solved-the-working-folder-source-path-is-already-in-use-by-the-workspace-workspace-name-owner-on-computer-tfs-server.aspx

http://stackoverflow.com/questions/8435135/change-computer-name-for-a-tfs-workspace

To list all workspace use:

tf workspaces /owner:* /computer:* /server:http://1.1.1.1:8080/tfs/MyCollection

To list detailed information on all workspaces, use:

tf workspaces /server:http://1.1.1.1:8080/tfs/MyCollection /computer:MyComputerName /owner:* /format:detailed

NOTE

In a specific case, deleting the workspace on the client was not enough. I had to execute the same command on the TFS server itself to delete both the client and de server workspace.