I am currently running (XD version 0.8.22.17) on (Windows 10 Version 10.0.15063).
When viewing a prototype within the (iOS mobile app version 1.2.5), I am presented with a missing fonts error message. Taking the example of Myriad Pro, the issue at first appeared to be with Typekit. Reinstalling the font seems to have resolved the Typekit issue, with the font now syncing correctly. However the missing font error remains when viewed on any other device or within the XD iOS app. Further investigation has revealed that all but the basic system fonts cause this error to persist.
Is this simply an issue of licensing across devices?
Glad you got things sorted with the local fonts with your desktop. In order to support the fonts on your local device, you'll need to have the fonts installed on your device, especially if you're loading from the Creative Cloud. We don't embed fonts due to the licensing issues.