Changing font size, font style, + color breaks assembly

[JessicaFrank]

Changed the font size, font style, and font color in a rich text element. They appeared as expected in Author. When I test assembled, the document was blank.

Removing those changes resulted in a document assembling as expected.

Haven't tested each change individually to see if one triggers the break or if it was the combo of them. Will add more detail below when I test further.