Yipes. I hate to be the bearer of bad news, but I’ve had errors like this with a whole host of art and animation programs(Photoshop, Illustrator, Paint Shop, Paint.net, GIMP, CAD, Wings, Blender, Aseprite). Unless you back up a copy somewhere else, that’s it. That’s why artists always save two copies of their work. All you can do is repair the damage the best you can and move on.
Also, to me, that error seems to mean one of four things:
- Aseprite encountered a memory leak which overflowed bounds and pushed out some important data(Possible).
- Your system isn’t reserving/allotting enough memory to Aseprite(Also, possible).
- Your GPU doesn’t have the power to handle the information(Highly unlikely).
- It was a simple save error(Most likely).