I also have the same issue . The key step for me was/is deleting the whole ./package directory that's created in the solution by nuget.
This works, but I have to delete it every time I want to run "manage nuget packages for solution". This was especially frustrating as it took a few goes to successfully install my package across multiple projects as I'd forgotten to check out some files. Each attempt I had to delete the package dir, restart VS, attempt to install my package (EntityFramework), and if there were any issues, start the whole thing over again as loading packages for solution would crash and there is no option to re-install a package for a specific project.
amazon kindle
This works, but I have to delete it every time I want to run "manage nuget packages for solution". This was especially frustrating as it took a few goes to successfully install my package across multiple projects as I'd forgotten to check out some files. Each attempt I had to delete the package dir, restart VS, attempt to install my package (EntityFramework), and if there were any issues, start the whole thing over again as loading packages for solution would crash and there is no option to re-install a package for a specific project.
amazon kindle