I have tested these changes, and has resolved the issue.
Thanks,
Brent
Weird, I tested adding a Webapi Controller using right-click Add Controller. First thing Visual Studio 2017 did was put Microsoft.VisualStudio.Web.CodeGeneration.Design (and all it's multiple dependencies) back into the Host project. then I had to attempt to create a controller a second time to add the controller, which worked.
So.... remove it in order to get Nuget to restore the packages in the solution. then, if you wish to generate the controllers it will automatically add back in these dependencies.
Personally, I will create the controller myself as the scaffolding doesn't inherit from <yourapp>ControllerBase.
I'm not sure how this will impact builds using a CI process that automatically restores the Nuget packages.
Personally, I don't like including packages in my server app who's purpose is to support development time processes.
Fun :)
OK, found the problem (through this post: <a class="postlink" href="https://github.com/dotnet/corefx/issues/18452">https://github.com/dotnet/corefx/issues/18452</a> )
You are including Microsoft.VisualStudio.Web.CodeGeneration.Design in the Host project. removing this package fixes the Nuget Restore.
Ok. looks good... except one question, if I create Host objects, are these host objects available across all tenants (shared and separate database?)