Are you using custom firmware? Or is it an unmodified Switch? I should've asked that before anything else, my bad for making assumptions. If it's an unmodified Switch then I'm not sure what the problem is. I'm not exactly an expert tbh. Did you try searching the error code online?
I searched and found a thread on here where someone fixed the error code you had when trying to update by recreating the update folder. It's not something you can do without custom firmware as far as I'm aware, though. So, that's the question, if you've installed cfw or not.
EDIT: Ah, never mind I see you made a separate thread, I'll read that one and see if I can help you out.