Ok, so I've tried every idea but nothing works to get my old file working. If I upload my save and someone who can run SDF removed its secure value, I wonder if it'll work?
If anyone wants to try: https://www.sendspace.com/file/j4ma3n
So yeah, lesson learned, never try to inject an older version of your savefile.
Edit: not even that worked. Thanks, Nintendo.
I've gave it a try just says that the savefile is corrupted.