Build error, This project references NuGet

Question

When I try to build my solution, I get the following error message:

Severity Code Description Project File Line Suppression State Error

Answer 1

Why should you need manipulations with packages.config or .csproj files?
The error explicitly says: Use NuGet Package Restore to download them.
Use it accordingly this instruction: https://docs.microsoft.com/en-us/nuget/consume-packages/package-restore-troubleshooting:

Quick solution for Visual Studio users
1.Select the Tools > NuGet Package Manager > Package Manager Settings menu command.
2.Set both options under Package Restore.
3.Select OK.
4.Build your project again.