Visual Studio 2013 Community Update 5 - unknown project type

Since updating my Visual Studio 2013 to Update 5 a few days ago, I have been unable to open a .NET Gadgeteer project in Visual Studio. I get the error about not being able to open that project type. I re-ran the “netmfvs2013.vsix” file that comes with the .NET Micro Framework, but it said it was already installed. Then I uninstalled Visual Studio 2013 Update 5 and reinstalled it. This time running “netmfvs2013.vsix” gave an error that it wasn’t a valid manifest. I think it is only Gadgeteer, because I have other projects that aren’t Gadgeteer and they open fine.

Has anyone else encountered this?

I was mistaken, it is not just Gadgeteer. I can’t open any of my projects.