Catastrophic Error in silverlight

Getting below exception in the silverlight XAML page (.XAML) whenever I drag the controls to the designer.

Exception: There was an error building the project. Please rebuild the project.

Exception: Catastrophic failure (Exception from HRESULT: 0x8000FFFF (E_UNEXPECTED))

Stack Trace:

at MS.Internal.XcpImports.CheckHResult(UInt32 hr) at MS.Internal.XcpImports.FrameworkElement_MeasureOverride(FrameworkElement element, Size availableSize) at System.Windows.FrameworkElement.MeasureOverride(Size availableSize) at System.Windows.FrameworkElement.MeasureOverride(IntPtr nativeTarget, Single inWidth, Single inHeight, Single& outWidth, Single& outHeight)

Do you have any idea?