Hi Mike,
We recommend to add the text as it should be present in control DOM tree - for example:
NRichTextView richTextView = (NRichTextView)nRichTextViewWithRibbonControl1.Widget.GetFirstDescendant(NRichTextView.NRichTextViewSchema);
richTextView.Content.Sections.Clear();
NSection section = new NSection();
richTextView.Content.Sections.Add(section);
NParagraph paragraph = new NParagraph();
section.Blocks.Add(paragraph);
NTextInline boldInline = new NTextInline("Bold Text.");
boldInline.FontStyleBold = true;
paragraph.Inlines.Add(boldInline);
NTextInline italicInline = new NTextInline("Italic Text.");
italicInline.FontStyleItalic = true;
paragraph.Inlines.Add(italicInline);
in short you need to create a section (controls pages) and then add paragraphs or tables to it. For more information you can check out Rich Text Editor \ Document Model topics which describe how a document is structured.
Hope this helps - let us know if you meet any problems or have any questions.
Best Regards,
Nevron Support Team