Recently I've cloned a quite large solution from a GIT repository and restored NuGet packages by right-clicking the solution and selecting "Restore NuGet Packages" from the list:
NuGet restore went fine:
But when I built the solution, I've got lots of "missing reference" warnings:
And build errors like this:
Invalid option '7.3' for /langversion; must be ISO-1, ISO-2, Default, Latest or a valid version in range 1 to 7.1.
To fix this, you can close the Visual Studio, delete the hidden .vs folder, open the solution in Visual Studio again, do Clean Solution, and Rebuild after that.
It's a bit of work, so I prefer to do first-time builds using MSBuild instead.
Make sure MSBuild and Nuget Commandline are inside your Path:
NuGet Commandline can be downloaded from the following link: https://www.nuget.org/downloads
MSBuild for Visual Studio 2019 is located here:
C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional\MSBuild\Current\Bin
Building solution from the command line
Now you can build your solutions from the command line like this.
nuget restore MySolution.sln
Building the solution:
msbuild MySolution.sln /t:build /m
/m will speed up your builds by telling MSBuild to use several cores.
NOTE: Replace MySolution.sln with your solution name
And that's it! No more warnings or build errors.