How can I troubleshoot vNext Release Management 2015 404 errors - ms-release-management

Question

I added a new vNext application, but when queuing its release, I get a very generic and unhelpful 404 error (pasted below). How can I troubleshoot this to figure out what is missing?
The vNext application looks to be almost identical to several other applications on my release management server, except for a component name and PowerShell script.
My challenge is that apart from the logging file located at "%TEMP%\Microsoft\ReleaseManagement\14.0\Logs\ReleaseManagementConsole.log", I can't seem to find any more information or events for this that would help me troubleshoot the issue further, even when enabling "Verbose" logging in the client web.config. Can anyone suggest ways that I can figure out what is missing? The only servers that I can think of that hit this are TFS (which is working as it can find the build), the destination web server (which exists as other releases are deploying to it), and the build server (which exists as other releases are deploying code from it).
3/22/2016 2:50:51 PM - Error - (19696, 16664) - The remote server returned an error: (404) Not Found.: \r\n\r\n at System.Net.HttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.TeamFoundation.Release.Data.WebRequest.PlatformHttpClient.EndGetResponse(IAsyncResult asyncResult)
at Microsoft.TeamFoundation.Release.Data.WebRequest.RestClientResponseRetriever.EndGetAsyncMemoryStreamFromResponse(IAsyncResult asyncResult, IPlatformHttpClient PlatformHttpClient)
at Microsoft.TeamFoundation.Release.Data.WebRequest.RestClientResponseRetriever.EndDownloadString(IAsyncResult asyncResult, IPlatformHttpClient PlatformHttpClient)
at Microsoft.TeamFoundation.Release.Data.WebRequest.RestClient.EndPost(IAsyncResult asyncResult)
at Microsoft.TeamFoundation.Release.Data.Proxy.RestProxy.HttpRequestor.<>c__DisplayClass0_0.<GetPostCaller>b__0(String url, String body)
at Microsoft.TeamFoundation.Release.Data.Proxy.RestProxy.BaseOrchestratorServiceProxy.InitiateRelease(String releaseTemplateName, IDictionary`2 deploymentPropertyBag)
at Microsoft.VisualStudio.Release.ViewModel.ViewModels.PipelineV2.ReleaseCreatorViewModelExtension.InvokeReleaseAction(ReleaseCreatorViewModel viewModel, Func`3 releaseAction, Func`2 releaseViewModelCreator, Func`3 longProcessCreator, Action`1 showViewAction, Func`2 loadReleases, Func`5 doesBuildExists)
at Microsoft.VisualStudio.Release.ViewModel.ViewModels.PipelineV2.ReleaseCreatorViewModel.<get_CreateAndStartCommand>b__120_0(Object param)
at Microsoft.VisualStudio.Release.ViewModel.Helpers.RelayCommandV2.Execute(Object parameter)
at MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
at System.Windows.Controls.Primitives.ButtonBase.OnClick()
at System.Windows.Controls.Button.OnClick()
at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
at System.Windows.Input.InputManager.ProcessStagingArea()
at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

Answer 1

Hi probably worth mentioning what version of RM you are using (2013 or 2015). In the early days of using 2013 I used to get this error due to a query string length error caused by having too many DSC/PS actions defined in my release template (from memory having more than 4 actions gave the 404 error). If that is the issue the workaround is mentioned towards the end of this link
https://social.msdn.microsoft.com/Forums/vstudio/en-US/a8f82f12-7dcc-496c-90e1-b71894ec9d34/the-remote-server-returned-an-error-404-not-found?forum=tfsbuild