From the FAQ Sticky Thread at the top of the Support Forum.
Q: Why don’t quotation marks work in Microsoft Word?
A: Word-processors often use autocorrect to convert the straight apostrophe (') and straight quote or inches character (") to typographical quotation marks (“), (”), (‘) and (’), also known as smart or curly quotes. If your font doesn’t have mappings to these characters, you will see rectangles instead. When the quotes aren’t showing at all, you need to add outlines to the corresponding glyphs. Make sure that your font contains all of the recommended glyphs.