Default URL handler ViewResult has a RuntimeBinderException

[coderandhiker]

If we invoke the following endpoint: http://wwtcoreapp-app-service.azurewebsites.net/learn/settingup

We fail with the following call stack:

Microsoft.CSharp.RuntimeBinder.RuntimeBinderException:
at CallSite.Target (Anonymously Hosted DynamicMethods Assembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null)
at System.Dynamic.UpdateDelegates.UpdateAndExecute1 (System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)
at ASP._Page_Views_Learn_SettingUp_cshtml.Execute (App_Web_foyhqc3k, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null)
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy (System.Web.WebPages, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.WebPages.StartPage.ExecutePageHierarchy (System.Web.WebPages, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy (System.Web.WebPages, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.ViewResultBase.ExecuteResult (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Async.AsyncControllerActionInvoker+<>c__DisplayClass3_1.b__1 (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Controller+<>c.b__152_1 (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Async.AsyncResultWrapper+WrappedAsyncVoid1.CallEndDelegate (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35) at System.Web.Mvc.Controller.EndExecuteCore (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35) at System.Web.Mvc.Async.AsyncResultWrapper+WrappedAsyncVoid1.CallEndDelegate (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Controller.EndExecute (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.MvcHandler+<>c.b__20_1 (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.Async.AsyncResultWrapper+WrappedAsyncVoid`1.CallEndDelegate (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.Mvc.MvcHandler.EndProcessRequest (System.Web.Mvc, Version=5.2.7.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35)
at System.Web.HttpApplication+CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute (System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
at System.Web.HttpApplication+<>c__DisplayClass285_0.b__0 (System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
at System.Web.HttpApplication.ExecuteStepImpl (System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)
at System.Web.HttpApplication.ExecuteStep (System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a)

[pkgw]

FWIW, content URLs like these (/Learn/SettingUp) have been offloaded to separate services (namely, wwt-user-website) and so don't need to be successful in the app service — but they should 404, not raise this error.

I am not sure where this error is coming in but here is that Default/ViewResult function that handles/handled these sorts of requests in the WWTMVC5 app:

wwt-website/src/WWTMVC5/Controllers/DefaultController.cs

Line 138 in d2f1052

[Route("{group}/{page=Index}")]