I recently upgraded all projects in a solution to .NET 4.7 and started seeing some NuGet warnings:
Essentially what seems to happen is that the NuGet package was installed when .NET 4.6 was the runtime target and this package may or may not need to be reinstalled (everything was functioning, but I just don’t like warnings when compiling).
Turns out there is no UI button for reinstalling a package, so the Package Manager Console is the place to go. The following command will reinstall the appropriate package for all project that use the package:
Update-Package -Id <package_name> –reinstall
Note that as soon as you’ve typed -Id you can use <Tab> to get a drop down list of installed packages.
For more variations of the command see: https://docs.microsoft.com/en-us/nuget/consume-packages/reinstalling-and-updating-packages