Test Explorer (VS) shows '<Unknown project>'

Everthing below is made in VS2019, using .NET Framework 4.7 and NUnit + NUnit3TestAdapter

I created an assembly called Exitus.Tests, and added a few unit tests. However, do to some issues with Nuget, that I could not solve, I made another project called Exitus.UnitTests and removed the once file I had in the old project (including changing the namespace).

Now the new test project showed op correctly in the explorer, but a "ghost" of the old project remained:

If I try to run the test, the output window shows the following error:

> System.InvalidOperationException: The following TestContainer was not found 'C:\Users\xxx\Source\Repositories\Expire\Exitus.Tests\bin\Debug\Exitus.Tests.dll' at Microsoft.VisualStudio.TestWindow.Client.TestContainer.TestContainerProvider.d__46.MoveNext() --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at Microsoft.VisualStudio.TestWindow.Controller.TestContainerConfigurationQueryByTestsBase.d__6.MoveNext() (...)

The stack trace is a lot longer, but the curious thing is the second line, stating that it could not find the test container at \Exitus.Tests\bin\Debug\Exitus.Tests.dll. This is the name of the old test project, which I removed and deleted. I have searched my entire project for the term Exitus.Tests and it returns no results.

Is there anyway to forcefully remove this 'ghost' project?

1. Close Visual Studio.
2. Delete the *.testlog files in: solutionfolder\.vs\solution name\v16\TestStore\number.

I faced the same issue right now. A cleanup helped. As I had cleanup issues with VS in the last time (some DB-lock prevents a real cleanup to happen), my working cleanup was this way:

1. Close VS.
2. Git Bash in solution folder: git clean -xfd

Probably it helps.

Neither of these solutions worked for me. I was able to get the test explorer working by closing visual studio and deleting the ".vs" folder. Then reopen the solution and let it rebuild it.

According to the Visual Studio developer community (found by going to the Help menu and selecting Feedback), an update to Visual Studio to version 16.5.5 will resolve the issue. FYI: They released this in February 2020

I can confirm it works (I was on VS 16.4.6)

Steps as below

1. Close Visual Studio

2. Go to the project folder

3. Find the ".vs" folder. (Make sure you are also checking hidden item)

4. Delete ".vs" folder.

5. Good to go, Open visual studio, build and run project.