title: Why does Visual Studio 2019 run tests in dotnet core 1.0 even though my projects target dotnet core 2.2?
body: <p>I have a solution with 2 projects, one of which is a test project. Both projects target dotnet core 2.2:</p>
  
  <pre><code>&lt;TargetFramework&gt;netcoreapp2.2&lt;/TargetFramework&gt;
  </code></pre>
  
  <p>I am using Visual Studio 2019 (version 16.1.1). When I click "Run all" in test explorer, it outputs this warning in output window:</p>
  
  <pre><code>[5/28/2019 10:25:40 PM Informational] ------ Run test started ------
  [5/28/2019 10:25:40 PM Warning] Test run will use DLL(s) built for framework .NETCoreApp,Version=v1.0 and platform X64. Following DLL(s) do not match framework/platform settings.
  MyApp.UnitTests.dll is built for Framework 2.2 and Platform AnyCPU.
  Go to http://go.microsoft.com/fwlink/?LinkID=236877&amp;clcid=0x409 for more details on managing these settings.
  
  [5/28/2019 10:25:41 PM Informational] ========== Run test finished: 3 run (0:00:01.167997) ==========
  </code></pre>
  
  <p>The tests do run, and finish successfully. But I am wondering about how to get rid of this warning.</p>
  
  <p>I added a .runsettings file with following settings, but I still see the same warning.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RunSettings&gt;
    &lt;RunConfiguration&gt;
      &lt;TargetFrameworkVersion&gt;FrameworkCore10&lt;/TargetFrameworkVersion&gt;
    &lt;/RunConfiguration&gt;
  &lt;/RunSettings&gt;
  </code></pre>
  
  <p>Changing FrameworkCore10 to FrameworkCore22 (or netcoreapp2.2) throws a huge exception. Top few lines of the exception:</p>
  
  <pre><code>[5/28/2019 10:41:30 PM Error] System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---&gt; System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---&gt; System.NullReferenceException: Object reference not set to an instance of an object.
     at Microsoft.VisualStudio.TestWindow.Controller.RequestConfiguration.GroupTestContainersConfigByFrameworkAndArchitecture(IEnumerable`1 testContainersConfig, IXPathNavigable runSetting)
     at Microsoft.VisualStudio.TestWindow.Controller.TestRunConfiguration.&lt;GetAllCriteriaQueues&gt;d__64.MoveNext()
     at Microsoft.VisualStudio.TestWindow.Controller.TestRunRequest.&lt;CreateRequests&gt;d__23.MoveNext()
     at Microsoft.VisualStudio.TestWindow.Controller.Request.&lt;RunRequests&gt;d__95.MoveNext()
     --- End of inner exception stack trace ---
  </code></pre>
  
  <p>Note that the same projects work fine in Visual Studio 2017, without the need of any runsettings file whatsoever.</p>