Cannot Create a new workbook or open existing one.

Windows 8 Pro
Xamarin Android installed
Xamarin for Visual Studio installed
Xamarin Studio intalled.

All above components are latest stable release.

I can develop my app and debug it within Visual Studio 2015, then I suppose the setup should be fine.

However, after I install Xamarin Workbook, when I create a new workbook, I got following error showing in log file

[Info][00:00:00] AppSession: Starting Xamarin Inspector client
[Error][00:00:10.6094299] AgentSessionWindow: unhandled exception: System.NullReferenceException: Object reference not set to an instance of an object.
at Xamarin.Inspector.Client.Android.AgentProcessFactories.AndroidAgentProcessFactory.<>c__DisplayClass4_0.b__2(AndroidDevice d)
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable1 source, Func2 predicate)
at Xamarin.Inspector.Client.Android.AgentProcessFactories.AndroidAgentProcessFactory.d__4.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 Xamarin.Interactive.Core.AgentCache.d__9.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 Xamarin.Interactive.Caching.ReferenceCountedCache3.<GetItemAsync>d__9.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 Xamarin.Interactive.Caching.ReferenceCountedCache3.d__8.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 Xamarin.Interactive.Core.AgentCache.d__5.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 Xamarin.Inspector.Windows.Client.AgentSessionWindow.d__50.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 Xamarin.Inspector.Windows.Client.AgentSessionWindow.d__48.MoveNext()

When I try to open a existing one ( the one I download from https://github.com/xamarin/Workbooks/blob/master/android/Views/PropertyAnimation.workbook

I got following error in log file:

[Info][00:00:00.0009791] AppSession: Starting Xamarin Inspector client
[Error][00:00:00.0832589] OpenWorkbook: unhandled exception: Xamarin.Interactive.Workbook.WorkbookDocumentModel+InvalidDocumentManifestException: The workbook does not contain a valid manifest.
at Xamarin.Interactive.Workbook.WorkbookDocumentModel.Read(FilePath path, TextReader reader)
at Xamarin.Interactive.Workbook.WorkbookDocumentModel.Open(FilePath path)
at Xamarin.Inspector.Windows.Client.App.OpenWorkbook(String path)

I can use workbook in Mac with Xamarin.iOS.

I have tried to use Xamarin Workbook with Android on two of my workstations, all of them get the same error.

Is this a bug ?