The "GetReferenceNearestTargetFrameworkTask" task was not found
I had the same error message but for a different problem.
So, I'm using MSBuild to automate build/deploy process for Azure Functions. Everything was working fine until I updated both Visual Studio 2017 and Visual Studio Build Tools 2017 at which point I started getting this error. To be precise I got this error only when using MSBuild, building project manually from VS was working fine.
In my case I already had everything set as per @Programmer's answer. But as I was using MSBuild it turned out that I also had to install NuGet targets and build tasks which are part of Visual Studio Build Tools.
Follow these to fix that error. This applies to VS 2017:
Fix 1:
1.Install Nuget PackageManager from here.
2.Restart Visual Studio.
If the problem is still there, continue below
Fix 2:
1.Download and start/run the Visual Studio Installer again.
2.While the Visual Studio Installer is still running, go to the "Individual Components" tab
3.Tick the "NuGet package manager" check-box that is under "Code tools" option.
4.Click Install to install it.
Screenshot of where this is located:
That should fix the error you see in this question. Restart Visual Studio and test the auto-completion function. If it's not working, see the answers from this question as that is a whole different issue.
I'm working with a headless build server on server core, resolved by installing chocolatey package choco install visualstudio2017-workload-webbuildtools from here:
https://chocolatey.org/packages?q=msbuild
I was seeing this issue with msbuild 15.6.82 on a build environment that does not have VisualStudio 2017, only VS Build Tools.
Here's a PowerShell script that resolves this issue, it pretty much does the equivalent of previous answers in the VS Installer, but silently and waiting for completion.
Start-Process "C:\Program Files (x86)\Microsoft Visual Studio\Installer\vs_installer.exe" -ArgumentList 'modify --installPath "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools" --quiet --add Microsoft.VisualStudio.Component.NuGet.BuildTools --add Microsoft.Net.Component.4.5.TargetingPack --norestart --force' -Wait -PassThru