MStest doesn't execute unit tests when OutputPath of the project changes

Igor M 6 Reputation points

When I change the OutputPath for my unit test project the tests are still discoverable in Test Explorer, but when I try to run them (right-click -> Run) they don't run and I get the error below in Output window. Why it suddenly doesn't find that dll?

Building Test Projects  
Starting test discovery for requested test run  
========== Starting test discovery ==========  
Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException: Testhost process exited with error: Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.TestPlatform.CoreUtilities, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'. The system cannot find the file specified.  
File name: 'Microsoft.TestPlatform.CoreUtilities, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'  
   at Microsoft.VisualStudio.TestPlatform.TestHost.Program.Main(String[] args)  
. Please check the diagnostic logs for more information.  
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.ThrowOnTestHostExited(Boolean testHostExited)  
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.SetupChannel(IEnumerable`1 sources, String runSettings)  
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyDiscoveryManager.DiscoverTests(DiscoveryCriteria discoveryCriteria, ITestDiscoveryEventsHandler2 eventHandler)  
========== Test discovery aborted: 0 Tests found in 859.1 ms ==========  
========== Starting test run ==========  
========== Test run finished: 0 Tests (0 Passed, 0 Failed, 0 Skipped) run in < 1 ms ==========  

The bin folder in the new OutputPath location seems to have all files that would have been in the bin folder inside the project folder if I haven't changed the OutputPath.

I use MStest from Visual Studio 2022.

What am I missing here?


Visual Studio Testing
Visual Studio Testing
Visual Studio: A family of Microsoft suites of integrated development tools for building applications for Windows, the web and mobile devices.Testing: The act or process of applying tests as a means of analysis or diagnosis.
334 questions
0 comments No comments
{count} vote

1 answer

Sort by: Most helpful
  1. Anna Xiu-MSFT 27,256 Reputation points Microsoft Vendor

    Hi @Igor M ,

    Welcome to Microsoft Q&A!

    Please try to rename (or delete) the hidden .vs, bin and obj folders in your project folder. Then run the tests again.

    If it doesn’t work, you can create a new test project and copy the code from the old test project.
    Please change the output path before running the tests.

    If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    1 person found this answer helpful.
    0 comments No comments