Can't seem to make FieldDisplayMode.DisplayName work correctly

[Pavel]

I am trying to create a template editor for making letters for mailing.
I open up a new form with a RadRichTextEditor and an Editor Ribbon, and then assign a MailMergeDataSource.ItemsSource.
I add a few fields to the documents, and then use a DocxFormatProvider to get a byte[]
That array goes into an event with a Letter object inside. The event handler code is below.
All I want to do, is reload that byte[] into a different RadRichTextEditor, and then display the mailmerge fields like this <<MyCustomField>> and ideally highlight it. Instead, it's just displaying data from the ItemsSource. Below is the code that I think is relevant

private void LetterEditor_TemplateSaved(object sender, TemplateSavedEventArgs templateSavedEventArgs)
{
    var provider = new DocxFormatProvider();
    var doc = provider.Import(templateSavedEventArgs.Letter.LetterByteArray);

    radRichTextEditor1.Document = doc;
   radRichTextEditor1.Document.ShowMergeFieldsHighlight = true;
    radRichTextEditor1.Document.FieldsDisplayMode = Telerik.WinForms.Documents.Model.FieldDisplayMode.DisplayName;
}

[Hristo]

Hello Pavel,

Thank you for writing.

Once you load the document in your new RadRichTextEditor instance you need to execute an update command. Please check my code snippet below: 

RadDocument doc = null;
DocxFormatProvider provider = new DocxFormatProvider();
using (Stream intput = File.OpenRead(@"..\..\merged-doc"))
{
    doc = provider.Import(intput);
}

this.radRichTextEditor2.Document = doc;
ChangeAllFieldsDisplayModeCommand command = new ChangeAllFieldsDisplayModeCommand(this.radRichTextEditor2.RichTextBoxElement);
command.Execute(FieldDisplayMode.DisplayName);
this.radRichTextEditor2.Focus();

I hope this helps. Please let me know if you need further assistance.

Regards,
Hristo Merdjanov
Telerik by Progress