I'm moving this question to the InDesign EPUB forum.
What font(s) are you using? The font may not be licensed for use in an EPUB.
I'm using typkit and some fonts free for educational use.
The fonts are: Tarajan and Servus Slab
I tried using simple fonts such as Times and didn't work either!
if you noticed, the font family does not even get to be specified in the export options.
Thank you for your response!
What do you expect here? Font Families are chosen in the Basic Character Formats.
BTW: Your screen shot shows 2 separate text frames. For EPUB export you have to create one single text frame and work with space before and after, otherwise both texts will stick on each other without a distance.
I'm creating a fixed layout ePub, so I think it's ok to have separate text frames.
i expected that the font family will be indicated in this box, because other working ePub files have that indicated.