This problem happening when your build tool is not set to do restore
on projects set to use PackageReference
vs packages.config
and mostly affect Net Core and Netstandard new style projects.
When you open Visual Studio and build, it resolves this for you. But if you use automation, CLI tools, you see this issue.
Many solutions are offered here. But all you need to remember, you need to force restore
. In some instances you use dotnet restore
before build. If you build using MsBuild just add /t:Restore
switch to your command.
Bottom line, you need to see why restoring can't be activated. Either bad nuget source or missing restore action, or outdated nuget.exe, or all of the above.