Dude, thank you so so much. You can't imagine the happy you made me with a thing like this. Keep helping others like this dude, you're such a great guy!
Here you go -- was missing the final block (0x200) of data which contains all the checksums. I truncated your save data to the correct size, then copied another OR/AS save file's last 0x200 bytes to the end of your save file, then opened & exported it with PKHeX to fix the checksums.
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