title: XUnit tests do not run in solution
body: <p>I cannot run any xunit tests in my solution. Visual studio test explorer finds them, but it seems the runner cannot find any.</p>
  
  <p>Specs:</p>
  
  <ul>
  <li>Visual studio 2017 15.9.13</li>
  <li>.NET Core 2.2</li>
  </ul>
  
  <p>The problem is specifically with XUnit test projects, because NUnit and MsTest projects run tests normally. All the packages in XUnit project are up to date (As of writing this post):  </p>
  
  <ul>
  <li>Microsoft.NETCore.App 2.2.0</li>
  <li>Microsoft.NET.Test.Sdk 16.3.0</li>
  <li>xunit 2.4.1</li>
  <li>xunit.runner.visualstudio 2.4.1</li>
  </ul>
  
  <p>Also, the problem is only in this solution, because in a new solution, xunit tests run normal.</p>
  
  <p>I have Diagnostic log level for tests, and what I see is that it says it cannot find any test.  </p>
  
  <p>This:</p>
  
  <pre><code>Test framework could not be determined for project: C:\path\to\my\project\XUnitTestProject1\bin\Debug\netcoreapp2.2\XUnitTestProject1.dll because reference path is null for at least one reference: Microsoft.NETCore.App
  </code></pre>
  
  <p>And this:</p>
  
  <pre><code>No test is available in C:\path\to\my\project\XUnitTestProject1\bin\Debug\netcoreapp2.2\XUnitTestProject1.dll. Make sure that test discoverer &amp; executors are registered and platform &amp; framework version settings are appropriate and try again.
  </code></pre>
  
  <p>My test class</p>
  
  <pre><code>using Xunit;
  
  namespace XUnitTestProject1
  {
      public class MyTestClass
      {
          [Fact]
          public void some_tests()
          {
              Assert.True(true);
          }
      }
  }
  </code></pre>
  
  <p>The full log in output panel</p>
  
  <pre><code>[10/21/2019 10:17:39 AM Diagnostic] About to Enqueue operation 'RunSelectedOperation', hashcode:37960157 
  [10/21/2019 10:17:39 AM Diagnostic] Enqueue operation 'RunSelectedOperation', hashcode:37960157 
  [10/21/2019 10:17:39 AM Diagnostic] Operation left in the the queue: 1
  [10/21/2019 10:17:39 AM Diagnostic]     'RunSelectedOperation', hashcode:37960157
  [10/21/2019 10:17:39 AM Diagnostic] 
  
  [10/21/2019 10:17:39 AM Diagnostic] Processing Queue .....
  [10/21/2019 10:17:39 AM Diagnostic] Operation Dequeue : 'RunSelectedOperation'
  [10/21/2019 10:17:39 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=OperationSetStarted, operationInProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=OperationSetStarted, InProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=ChangeDetectionStarting, operationInProgress=True
  [10/21/2019 10:17:39 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=ChangeDetectionStarting, InProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] We programmatically start the build in TestWindowHost.UpdateContainer... 
  [10/21/2019 10:17:39 AM Diagnostic] After we await the build that programmatically started in TestWindowHost.UpdateContainer... 
  [10/21/2019 10:17:39 AM Diagnostic] TestContainer update (build) complete : 405 ms
  [10/21/2019 10:17:39 AM Diagnostic] Time taken for fetching Roslyn supported projects: 0 milliseconds.
  [10/21/2019 10:17:39 AM Diagnostic] DiscoveryOperation&lt;RunSelectedOperation&gt; FinishedChangedCotainers, changed container count is 0
  [10/21/2019 10:17:39 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=ChangeDetectionFinished, operationInProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] Test framework could not be determined for project: C:\path\to\my\project\XUnitTestProject1\bin\Debug\netcoreapp2.2\XUnitTestProject1.dll because reference path is null for at least one reference: Microsoft.NETCore.App
  [10/21/2019 10:17:39 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=ChangeDetectionFinished, InProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=TestExecutionStarting, operationInProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=TestExecutionStarting, InProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=TestExecutionStarted, operationInProgress=False
  [10/21/2019 10:17:39 AM Informational] ------ Run test started ------
  [10/21/2019 10:17:39 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=TestExecutionStarted, InProgress=False
  [10/21/2019 10:17:39 AM Diagnostic] RunSettings Content:
  &lt;RunSettings&gt;
    &lt;RunConfiguration&gt;
      &lt;ResultsDirectory&gt;C:\path\to\my\project\TestResults&lt;/ResultsDirectory&gt;
      &lt;SolutionDirectory&gt;C:\path\to\my\project\&lt;/SolutionDirectory&gt;
      &lt;TargetPlatform&gt;X64&lt;/TargetPlatform&gt;
      &lt;TargetFrameworkVersion&gt;Framework45&lt;/TargetFrameworkVersion&gt;
    &lt;/RunConfiguration&gt;
  &lt;/RunSettings&gt;
  [10/21/2019 10:17:39 AM Diagnostic] Value of UseSpecifiedAdapterLocations as specified in Tools -&gt; Options: True
  [10/21/2019 10:17:39 AM Diagnostic] Value of FallbackToGlobalVsix as specified in Tools -&gt; Options: True
  [10/21/2019 10:17:39 AM Diagnostic] Adapter location settings being used after evaluation: UseSpecifiedAdapterLocations = False, SkipDefaultAdapters = False, AreAllTestContainersCSharpOrVBProjectsOnly = True
  [10/21/2019 10:17:39 AM Diagnostic] Final RunSettings for the current TestRunCriteria:
  &lt;RunSettings&gt;
    &lt;RunConfiguration&gt;
      &lt;ResultsDirectory&gt;C:\path\to\my\project\TestResults&lt;/ResultsDirectory&gt;
      &lt;SolutionDirectory&gt;C:\path\to\my\project\&lt;/SolutionDirectory&gt;
      &lt;TargetPlatform&gt;X64&lt;/TargetPlatform&gt;
      &lt;TargetFrameworkVersion&gt;FrameworkCore10&lt;/TargetFrameworkVersion&gt;
      &lt;CollectSourceInformation&gt;False&lt;/CollectSourceInformation&gt;
    &lt;/RunConfiguration&gt;
  &lt;/RunSettings&gt;
  [10/21/2019 10:17:40 AM Warning] No test is available in C:\path\to\my\project\XUnitTestProject1\bin\Debug\netcoreapp2.2\XUnitTestProject1.dll. Make sure that test discoverer &amp; executors are registered and platform &amp; framework version settings are appropriate and try again.
  [10/21/2019 10:17:40 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=OperationSetFinished, operationInProgress=False
  [10/21/2019 10:17:40 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=OperationSetFinished, InProgress=False
  [10/21/2019 10:17:40 AM Diagnostic] ***    Run finished using 'InMemoryUnitTestWriter' ***
  [10/21/2019 10:17:40 AM Informational] ========== Run test finished: 0 run (0:00:00.7402273) ==========
  [10/21/2019 10:17:40 AM Diagnostic] VirtualReadOnlyTestDataStore.OperationStateChanged State=TestExecutionFinished, operationInProgress=False
  [10/21/2019 10:17:40 AM Diagnostic] TestDiscoveryStats.OperationStateChanged State=TestExecutionFinished, InProgress=False
  
  </code></pre>