I'm trying to upload a ttf font which works on my PC and in other Adobe apps. Express won't let me upload it, claiming it's "not a font". See screenshots
Well, this is confusing because I've successfully added other custom fonts to my account. It's only this specific one that seems to be a problem. I instead found a visually similar font "Slayer" which I downloaded and then added to my account without issue
To use custom fonts, you must have a paid enterprise account. You can request access to a custom font from the Admin of the enterprise account who will then share the custom font with you through the Admin Console.