Commented Issue: Can't install any package using nuGet package manager in Visual Studio [3068]

I just updated the nuGet Package manager. The version number is 2.2.40... Now, I am trying to install one package using nuGet Package Manager. and it is throwing an error. It is happening with only one web project. I have other web projects where I could install that package successfully. The error message is below:

" Access to the path 'C:\Users\kpatel\documents\visual studio 2010\Projects\CorpEmailManager\CorpEmailManager\packages.config' is denied. At line:1 char:16 + Install-Package <<<< Microsoft.AspNet.Mvc.FixedDisplayModes + CategoryInfo : NotSpecified: (:) [Install-Package], UnauthorizedAccessException + FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand"


I am attaching my package.config file also.


Thanks in advance for help.
Comments: Have you tried explicitly checking the file out from TFS before doing the install-package? This seems like the file is marked as readonly and cannot be edited by NuGet when the package is being installed. Since this is only happening in a single project, it seems like there's something wrong with that particular file. Are you able to check the file out and edit it through VS yourself, or even notepad?