The 'minClientVersion' attribute is not declared
I ran into this problem trying to install a NuGet package, Fody. I couldn't find any solutions to this by searching online, so I thought I'd write a quick blog post about my solution. It's pretty easy which is probably why I couldn't find a solution.
Solution: In Visual Studio click Tools->Extensions and Updates...
In the updates group, you will find NuGet Package Manager. Click Update. Go ahead and let the package update. Restart Visual Studio if necessary.
Following that, I was able to install the Fody package.