Hi Warner,
Sorry to hear about the trouble. Generally, if the data get lost because of application crash we can try to recover the file from this location: \Users\username\AppData\Local\Packages\Adobe.CC.XD_adky2gkssdxte\LocalState
Also if any file gets corrupted then we lose the entire data and the file becomes un-accessible however as you confirmed that you are able to open the file, I suspect somehow the file content was overwritten with the last change. If it was a cloud document we could have checked the last version of the file on your end, however since its a local file, I am afraid, we don't have many options in this situation.
Regards
Rishabh