Does Altium Designer have autosave? (I hope so - even every Microsoft Office product has autosave, web browsers will recover tabs after a crash, etc. It's pretty much just expected).
If AD has this "feature" and it has been removed from Circuit Studio which is just a cut down AD then that implies malice on the part of Altium. It's one thing not being able to have advanced stuff like FPGA pin swap or impedence matched squiggly wiggly track routing. But to deliberately remove a data recovery feature is disgusting.
I can't imagine any of the developers OK'd this, but pointy headed MBA's actually thought "Haha - if the stupid nerds didn't back up their CS stuff, maybe they will look at paying out for AD instead." Good Idea!
ETA: "Hell, it will make them go for our Cloud backup stuff and Internet of Shit!"
Also, surely the reason for the data recovery is because AD or CS crashed due to Altiums bugs to begin with!