How can I debug unit test in Visual Studio 2017 15.6.0

Question

Brand new machine, new install of Visual Studio 2017 Enterprise 15.6.0. I cannot seem to debug tests. I get the following error:

Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException: Failed to launch testhost with error: System.AggregateException: One or more errors occurred. () ---> Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException
   at Microsoft.VisualStudio.TestPlatform.Client.DesignMode.DesignModeClient.LaunchCustomHost(TestProcessStartInfo testProcessStartInfo)
   at Microsoft.VisualStudio.TestPlatform.Client.DesignMode.DesignModeTestHostLauncher.LaunchTestHost(TestProcessStartInfo defaultTestHostStartInfo)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.LaunchHost(TestProcessStartInfo testHostStartInfo, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.<>c__DisplayClass37_0.<LaunchTestHostAsync>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.<LaunchTestHostAsync>d__37.MoveNext()
   --- End of inner exception stack trace ---
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.SetupChannel(IEnumerable`1 sources, CancellationToken cancellationToken)
---> (Inner Exception #0) Microsoft.VisualStudio.TestPlatform.ObjectModel.TestPlatformException
   at Microsoft.VisualStudio.TestPlatform.Client.DesignMode.DesignModeClient.LaunchCustomHost(TestProcessStartInfo testProcessStartInfo)
   at Microsoft.VisualStudio.TestPlatform.Client.DesignMode.DesignModeTestHostLauncher.LaunchTestHost(TestProcessStartInfo defaultTestHostStartInfo)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.LaunchHost(TestProcessStartInfo testHostStartInfo, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.<>c__DisplayClass37_0.<LaunchTestHostAsync>b__0()
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
--- End of stack trace from previous location where exception was thrown ---
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Hosting.DotnetTestHostManager.<LaunchTestHostAsync>d__37.MoveNext()<---

   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyOperationManager.SetupChannel(IEnumerable`1 sources, CancellationToken cancellationToken)
   at Microsoft.VisualStudio.TestPlatform.CrossPlatEngine.Client.ProxyExecutionManager.StartTestRun(TestRunCriteria testRunCriteria, ITestRunEventsHandler eventHandler)
 Summary: Passed: 0, Failed: 0, Ignored: 0
Duration: 4.82 seconds

I can however run the test, but I need to step DEBUG through my tests.

Answer 1

If you are use a VPN connection, first disconnect VPN,then close VS2017 and reopen

Answer 2

If you are using VS2017, update your projects to use netcore 2.0 and it will work.

Had the same problem after installing VS2017 and trying to debug projects that I had created with netcore 1.0.