It's a UXA project.
I use a custom font (.xpr taken from the disk) that I first add to my project.
Then I save it. It works.
Finally I re-open the same UXA project, and re-save it (with or wthout changing anything else), always as an UXA project.
=> The fonts are back to Square_10
I saw another error:
It seems that UXA is not keeping the Globe, Orb and Fog informations in a UXA project. Just create a new UXA from scratch, check Use Globe, Use Orb and Use Fog and save your UXA file (I always use the Save as UXA option).
Exit UXA, and relaunch it. On the welcome screen select your project.
=> it opens with Use Globe, Use Orb and Use Fog unchecked (XML is consistent, no globe, orr or fog).
Don't hesitate if you need more testing, I have some time
