Hax fails to write to cart

[backlash52]

Unable to use Sploit as i have Luma running on a CFW system. Trying to apply the hax from a CFW system to run homebrew on a stock N3DSX to back up save data. When i try to use JKSV to write one of the saves back to the cart nothing happens. Trying to copy said save results in an out of memory error on the cart due to the filesize. I noted in the instructions it says to make sure they're the same size but i have no idea how to make that happen. Any suggestions on what im missing?