Thank you so much @TurdPooCharger.
For everyone who lost hope and it has seemed like you have tried every thing. If you have the same error upon booting up your 3ds as the original poster did. Then do try what @TurdPooCharger had mentioned with the decrypt9 ctrtransfer.
I have this exact problem too. I have tried everything posted in this thread except for decrypt9 (If anyone could explain to me how) however, my 3ds still does not work.
If anyone that passes by has a fix, I would be much appreciated