Visual Studio 2015 InspectorPackage package did not load correctly

I have a fresh install of Windows 10, Visual Studio 2015 Update 3, and the latest Xamarin. I get the following error:

The 'InspectorPackage' package did not load correctly.

Here is the info from the activity log:

<entry>
    <record>673</record>
    <time>2016/12/27 08:31:15.065</time>
    <type>Error</type>
    <source>VisualStudio</source>
    <description>LegacySitePackage failed for package [InspectorPackage]Source: &apos;&apos; Description: The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))&#x000D;&#x000A;System.ArgumentException: The parameter is incorrect. (Exception from HRESULT: 0x80070057 (E_INVALIDARG))&#x000D;&#x000A;   at EnvDTE.Properties.Item(Object index)&#x000D;&#x000A;   at Xamarin.Inspector.VS.VSAgentExecutionTarget..ctor(Project proj)&#x000D;&#x000A;   at Xamarin.Inspector.VS.VSInspectorSession.CreateAgentExecutionTarget()&#x000D;&#x000A;   at Xamarin.Interactive.IdeSupport.InspectorSession.Prepare()&#x000D;&#x000A;   at Xamarin.Inspector.VS.InspectorPackage.RefreshInspectorSession()&#x000D;&#x000A;   at Xamarin.Inspector.VS.InspectorPackage.Initialize()&#x000D;&#x000A;   at Microsoft.VisualStudio.Shell.Package.Microsoft.VisualStudio.Shell.Interop.IVsPackage.SetSite(IServiceProvider sp)</description>
    <guid>{0FCBA9C6-0554-418C-8B79-FF2ED7DC658D}</guid>
    <hr>80070057 - E_INVALIDARG</hr>
    <errorinfo></errorinfo>
  </entry>

Any idea how to resolve?