I am reviewing “Your First Script” in the " Complete C# Unity Game Developer 3D Online Course - 2020" and I get a notification of a Error. It has a pop up that says “Some projects have trouble loading. Please review the output for details.”
So I click on the “Show Output” button in the popup message which brings up the Debug section of the C# script program at the bottom of the coding page and it says:
i:\Unity2\Unity 3D\Experimenting\Assembly-CSharp.csproj
C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools\MSBuild\Current\Bin\Microsoft.Common.CurrentVersion.targets(1177,5): Error: The reference assemblies for .NETFramework,Version=v4.7.1 were not found. To resolve this, install the Developer Pack (SDK/Targeting Pack) for this framework version or retarget your application. You can download .NET Framework Developer Packs at https://aka.ms/msbuild/developerpacks
Attempted to update project that is not loaded: i:\Unity2\Unity 3D\Experimenting\Assembly-CSharp.csproj
What does all that mean?