Silverlight Application Error 0x17F8 RRS feed

  • Question

  • I have several similar comboboxes with custom templates that display one custom control on the dropdown. Suddenly one of those controls have broken and they give me the following error when I open the combobox

    Message: Unhandled Error in Silverlight 4 Application Error 0x17F8.  Debugging resource strings are unavailable. See http://go.microsoft.com/fwlink/?linkid=106663&Version=4.0.50401.0&File=mscorrc.dll&Key=0x17F8   at <INSERT_NAMESPACE>.ComboBox_DropDownOpened(Object sender, EventArgs e)
       at System.Windows.Controls.ComboBox.OnDropDownOpened(EventArgs e)
       at System.Windows.Controls.ComboBox.OnIsDropDownOpenChanged(Boolean isDropDownOpen)
       at System.Windows.Controls.ComboBox.OnIsDropDownOpenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
       at System.Windows.DependencyObject.RaisePropertyChangeNotifications(DependencyProperty dp, Object oldValue, Object newValue)
       at System.Windows.DependencyObject.UpdateEffectiveValue(DependencyProperty property, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, ValueOperation operation)
       at System.Windows.DependencyObject.SetValueInternal(DependencyProperty dp, Object value, Boolean allowReadOnlySet)
       at System.Windows.DependencyObject.SetValue(DependencyProperty property, Boolean b)
       at System.Windows.Controls.ComboBox.ElementDropDownToggle_Click(Object sender, RoutedEventArgs e)
       at System.Windows.Controls.Primitives.ButtonBase.OnClick()
       at System.Windows.Controls.Primitives.ToggleButton.OnClick()
       at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
       at System.Windows.Controls.Control.OnMouseLeftButtonUp(Control ctrl, EventArgs e)
       at MS.Internal.JoltHelper.FireEvent(IntPtr unmanagedObj, IntPtr unmanagedObjArgs, Int32 argsTypeIndex, String eventName)
    Line: 1
    Char: 1
    Code: 0

    As you can see this only happens in deployed release versions and on the machines with no development environments. The same release version (and debug version) is working on my development machine.

    I tried to Google the error but so far haven't found anything that would be helpful. Any advice how to start solving this? Could this be related to Silverlight runtime version or something that should be installed on the release machines as well?

    Tuesday, November 9, 2010 3:10 AM


  • I managed to solve the issue. I installed Developer Runtime to the machine for the hope that it would reveal better error message from the Exception. And it did! The issue was in the code of the control that was being displayed in the combobox dropdown. I fixed the bug and it's now working fine. Apparently even the strangest error message can mean the simplest thing :)

    Wednesday, November 10, 2010 12:19 AM