144
votes

I can't run my unit tests.

I have the next error:

Your project does not reference ".NETFramework,Version=v4.6.2" framework. Add a reference to ".NETFramework,Version=v4.6.2" in the "TargetFrameworks" property of your project file and then re-run NuGet restore.

In app.config:

<startup>
  <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2"/>
</startup>

In Project > Properties > Application > TargetFramework (.NET Framework 4.6.2)

How can I fix it?

9

9 Answers

352
votes

Please make the next steps

  1. Clean solution
  2. Clean folder "packages"
  3. Delete folder "bin"
  4. Delete folder "obj"
41
votes

I experienced similar issue, but with v4.7.2. Namely, I kept getting build log message like this:

error : Your project does not reference ".NETFramework,Version=v4.7.2" framework. Add a reference to ".NETFramework,Version=v4.7.2" in the "TargetFrameworks" property of your project file and then re-run NuGet restore.

Despite the fact that it looked similar, none of the above proposed steps worked for me. I kept seeing this message after each build. Nothing seemed to be able to help.

In fact, the problem was related to that, due to migration, I had to put two projects in one folder of code. One of them was targeted at .Net Core, another at .Net Framework, both referenced same .Net Standard libraries. Apparently, they share the same obj folder where Core projects put project.assets.json file. Actually, exactly this file interferres with the Framework project preventing its normal build. Seems even if you performed Migrate from packages.config to PackageReference... which was recommended as one of possible solution.

You can try to fix the issue by putting the following snippet into your Framework project file:

<Project>
  ...
  <PropertyGroup>
    <BaseOutputPath>$(MSBuildProjectDirectory)/out/$(MSBuildProjectName)/bin</BaseOutputPath>
    <BaseIntermediateOutputPath>$(MSBuildProjectDirectory)/out/$(MSBuildProjectName)/obj</BaseIntermediateOutputPath>
  </PropertyGroup>
  ...
</Project>

It immediately worked for me, it was only later when I attentively read why we need it and why it works. I unexpectedly found it in part 2 of Migrating a Sample WPF App to .NET Core 3 under Making sure the .NET Framework project still builds section. BaseOutputPath and BaseIntermediateOutputPath msbuild variables can be found there, not sure if they are documented well anywhere.

31
votes

That happened to me when opening a VS2015 project in VS2017. Deleting the project.assets.json from the obj folder did the trick.

Anyway, the Framework from the message was missing in the file, I did not add it there though, went with deleting it.

16
votes
git clean -xdf

That should do the trick. It worked for us also in Jenkins. (we simply replayed the failed build with a modified script that ran git clean first).

For some reason MSBuild / Visual Studio get confused when switching between branches that target different versions of .NET Framework, so I had to do git cleans regularly while switching between branches.

5
votes

I up-voted Larissa but I thought it might be helpful to know how I got into this. I added a .net standard project file to my build (we target lots of platforms) and it produced the debris found in the obj folder. When the android sanity build came around, it threw up on the obj folder. My solution was to clean that folder out as a pre-build step. This is a difficult problem because it was working just fine for years...needle meet haystack.

3
votes

I ran into the same thing with .net 4.71. In my case, I simply migrated from packages.config to "package references" per

Migrate from packages.config to PackageReference

... and it fixed my issue. For me, I was going to do this anyway, so if you're going this way already, I'd just skip the above and migrate to package references.

3
votes

For my case, delete the .pkgrefgen/ folder under the project folder works, it contains a file project.assets.json that refer to old .net framework

1
votes

Renaming the project solved the error for me. The issue happened after I created .NET Core project, then I deleted it and created a .NET Standard one with the same name. Obj folder was not present at all. Deleting bin folder, packages, clean and rebuild solution and getting latest with override did not help.

I have not tried this, but this thread proposed workaround is to include into csproj tag:

<ResolveNuGetPackages>false</ResolveNuGetPackages>
0
votes

I am using a very old .NET project, and it was working fine until it stopped all of a sudden. Upgrading Visual Studio fixed for me thou.