Commented Unassigned: Input string was not in a correct format [3609]

I have upgrade to the latest NuGet version 2.7, and I now get the following error when trying to install a package. I am running on VS2012 Ultimate. I had all of the latest updateds installed. I did just install an update to VS for I believe the Windows Phone 8 that was in the extensions list. I also just installed the latest version of Typescript.

PM> install-package log4net
Installing 'log4net 2.0.0'.
Successfully installed 'log4net 2.0.0'.
Adding 'log4net 2.0.0' to Tyson.OperatorUpload.
Install failed. Rolling back...
install-package : Input string was not in a correct format.
At line:1 char:1
+ install-package log4net
+ ~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], FormatException
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PowerShell.Commands.InstallPackageCommand

PM>
Comments: I tried the scenario on NuGet 2.7 + VS 2012 and was not able to repro Install-Package nbehave 'nbehave 0.6.2' already installed. Adding 'nbehave 0.6.2' to UnitTestProject1. Successfully added 'nbehave 0.6.2' to UnitTestProject1. install-package log4net Installing 'log4net 2.0.0'. Successfully installed 'log4net 2.0.0'. Adding 'log4net 2.0.0' to MvcApplication1. Successfully added 'log4net 2.0.0' to MvcApplication1. 1. Can you please try to install it on a vanilla project and see if it works for you. This might help to narrow down the repro to see if there is anything specific in your solution that's causing it to fail. Can you share a narrowed down project that fails. 2. Are you able to install the same package on the project where it repros from package manage dialog? Thanks