Hello
I believe the DOCX writer add-on may have a bug. If I create and save a RTF document using WRichText v7.23, then open it again and save it as DOCX, some fonts get replaced in Microsoft Word.
Try that:
1-create a new document in WPRichText
2-write "this lines uses Courier New"
3-jump 2 lines and write "this line uses Arial".
4-format the fonts accordingly to what the text says
5-save the document as a RTF
6-reopen it
7-save it as DOCX
8-open it using Microsoft Office 2013
In my case, the Arial font is replaced by Courier new on the second line.
