Fonts, transparencies and other effects used in vector format softwares (Illustrator and InDesign) must be flattened and the fonts outlined. Not flattening transparencies or outlining fonts may result in some text or graphics dropping out from your artwork.

Adobe Illustrator
Adobe InDesign

Adobe Illustrator
To flatten transparency and outline the fonts please use the instruciton below. - How to check if my font/object dropped out.

Select All (Ctrl A / Cmd A) Object > Flatten Transparency