Some time ago, you had to follow some confusing steps to copy sysnand to emunand, unlink them and make eshop work on emunand.Is there any "proper steps" guide like the extremely detailed A9LHax guide? I really don't want to mess anything up and lose all my stuff.
You had to create your emunand as a clone of your sysnand (that means, two "systems" sharing the SD's extdata folder, they're linked).
To unlink them, you would need to format sysnand (to generate a new extdata folder only for sysnand and unlinking your NNID from sysnand).
The thing is that when you format a system, you're saying to nintendo servers that you will not use that NNID until you relink it into another system or something in a future.
The problem is that you have your NNID on your emunand, so when you go to eshop, you're trying to use a NNID that is not suposed to be in use, hence, an error.
To fix it, you need to format emunand, go to system settings in this now empty emunand and relink your NNID (saying to nintendo servers "hey, I'm using this NNID again"). Once done, reinject your emunand.bin/nand.bin on your emunand and paste the SD content you had when you dumped before all this process.
Now you can simply use tinyformat on sysnand.
With that you can format sysnand (creating a new extdata folder for sysnand) without connecting to internet and without saying to nintendo servers that you will not use the current NNID (because you want to use it on emunand).
I don't know if I have left something behind...