System.ArgumentException: 'Requested distance is outside the content of the associated document.'PresentationFramework.dll!System.Windows.Documents.TextPointer.TextPointer(System.Windows.Documents.TextContainer textContainer, int offset, System.Windows.Documents.LogicalDirection direction)
  PresentationFramework.dll!System.Windows.Documents.TextContainer.CreatePointerAtOffset(int offset, System.Windows.Documents.LogicalDirection direction) 
  PresentationFramework.dll!System.Windows.Documents.TextParentUndoUnit.Do() 
  PresentationFramework.dll!MS.Internal.Documents.UndoManager.Redo(int count) 
  PresentationFramework.dll!System.Windows.Documents.TextStore.RedoQuietly(int count)  PresentationFramework.dll!System.Windows.Documents.TextStore.SetFinalDocumentState(MS.Internal.Documents.UndoManager undoManager, System.Collections.Stack imeChangeStack, int appChangeCount, int imeSelectionAnchorOffset, int imeSelectionMovingOffset, int appSelectionAnchorOffset, int appSelectionMovingOffset)  PresentationFramework.dll!System.Windows.Documents.TextStore.HandleCompositionEvents(int previousUndoCount)  PresentationFramework.dll!System.Windows.Documents.TextStore.GrantLockWorker(MS.Win32.UnsafeNativeMethods.LockFlags flags)   PresentationFramework.dll!System.Windows.Documents.TextStore.RequestLock(MS.Win32.UnsafeNativeMethods.LockFlags flags, out int hrSession)

private void RadSpreadsheet_Loaded(object sender, RoutedEventArgs e)
{
    var hyperlinkDialog = this.spreadsheet.ActiveWorksheetEditor.Dialogs.HyperlinkDialog as HyperlinkDialogContent;
    hyperlinkDialog.Loaded += HyperlinkDialog_Loaded;
}

private void HyperlinkDialog_Loaded(object sender, RoutedEventArgs e)
{
    var dialog = (HyperlinkDialogContent)sender;
    var screenTipLocalizedText = LocalizationManager.Manager.GetStringOverride("Spreadsheet_InsertHyperlinkDialog_ScreenTip");
    var screenTipTb = dialog.ChildrenOfType<TextBlock>().FirstOrDefault(x => x.Text == screenTipLocalizedText);
    if (screenTipTb != null)
    {
        screenTipTb.VerticalAlignment = VerticalAlignment.Center;
    }            
}