“Unhandled Error in Silverlight Application Code: 4004 Category: ManagedRuntimeError

A Silverlight web application which has multiple child windows  poping up to handle various event on different pages, gave the following error:

“Unhandled Error in Silverlight Application
Code: 4004
Category: ManagedRuntimeError
Message: System.ArgumentException: Content for the URI cannot be loaded. The URI may be invalid.
Parameter name: uri
at System.Windows.Navigation.NavigationService.NavigateCore(Uri uri, NavigationMode mode, Boolean suppressJournalAdd, Boolean isRedirect)
at System.Windows.Navigation.NavigationService.Journal_Navigated(Object sender, JournalEventArgs args)
at System.Windows.Navigation.Journal.OnNavigated(String name, Uri uri, NavigationMode mode)
at System.Windows.Navigation.Journal.UpdateObservables(JournalEntry currentEntry, NavigationMode mode)
at System.Windows.Navigation.Journal.AddHistoryPoint(JournalEntry journalEntry)
at System.Windows.Navigation.Journal.AddHistoryPointIfDifferent(String newState)
at System.Windows.Navigation.Journal.CheckForDeeplinks()
at System.Windows.Controls.Frame.ApplyDeepLinks()
at System.Windows.Controls.Frame.Frame_Loaded(Object sender, RoutedEventArgs e)
at MS.Internal.CoreInvokeHandler.InvokeEventHandler(Int32 typeIndex, Delegate handlerDelegate, Object sender, Object args)
at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, Int32 actualArgsTypeIndex, String eventName)
”

I had absolutely no clue why this was happening until I decided to break down the error situation.

PROBLEM:

The presence of a “<sdk:Frame />” control was the cause for all the headache.

Silverlight toolbox: Frame and rectangle controls

FIX:

Removing the Silverlight Frame control saved my day.

Follow this link to learn how to use the frame control correctly without causing errors: http://blogs.microsoft.co.il/blogs/alex_golesh/archive/2009/04/02/silverlight-3-quick-tip-6-navigation-framework-and-uri-routing.aspx

The trick is to understand the navigation-framework-uri-routing thingy !