Azure Web App with ADFS for authentication - Unable to create to obtain configuration from federationmetadata

Question

I'm trying to setup an Azure Web App to use an ADFS server for authentication (which is also hosted on a VM on azure). I'm using a .NET MVC project which was auto-generated by visual studio. I'm only using this for testing. I changed the 'authentication' when creating the project to point at my federation.xml file. Here is the stack trace output:

[InvalidOperationException: IDX10803: Unable to create to obtain configuration from: https://<DNS-OF-ADFS-SERVER>.eastus.cloudapp.azure.com/federationmetadata/2007-06/federationmetadata.xml'.]
   Microsoft.IdentityModel.Protocols.<GetConfigurationAsync>d__3.MoveNext() +1781
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.WsFederation.<ApplyResponseChallengeAsync>d__c.MoveNext() +433
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.Infrastructure.<ApplyResponseCoreAsync>d__b.MoveNext() +282
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.Infrastructure.<ApplyResponseAsync>d__8.MoveNext() +275
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.Infrastructure.<TeardownAsync>d__5.MoveNext() +160
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.Infrastructure.<Invoke>d__0.MoveNext() +815
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<RunApp>d__5.MoveNext() +182
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Security.Infrastructure.<Invoke>d__0.MoveNext() +638
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<RunApp>d__5.MoveNext() +182
   System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +92
   System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +58
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.<DoFinalWork>d__2.MoveNext() +180
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar) +69
   Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.EndFinalWork(IAsyncResult ar) +65
   System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +380
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

I'm using a self-signed certificate. The federationmetadata page loads fine in Microsoft Edge.

The only thing I altered was in the web.config file:

<add key="ida:ADFSMetadata" value="https://<DNS-OF-ADFS-SERVER>.eastus.cloudapp.azure.com/federationmetadata/2007-06/federationmetadata.xml"/>
<add key="ida:Wtrealm" value="https://<AzureWebAppName>.azurewebsites.com/" />