NuGet Package restore failed for project Miscellaneous Files: Value cannot be null or an empty string. Parameter name: root. 0 0

Question

I have such error in vs 2012: NuGet Package restore failed for project Miscellaneous Files: Value cannot be null or an empty string. Parameter name: root. 0 0

I see

Answer 1

I uninstalled and reinstalled nUnit 3.7.1 and everything started working again. I have a few nuget packages, but nunit 3.7.1 is the only one I reinstalled, I left the rest alone.