I can not add fonts to xibo version 1.7.8

I can add a font, but the font does not display the text. Is there enough ways to introduce me?
Thank you vary much

Have you ‘installed’ the font (Edit&Save) and cleared your browser cache afterwords? http://xibo.org.uk/manual/en/media_module_font.html

Yes, I did. I followed the steps you told me, but the text that was inserted did not show up.