I figured out how to do this.
Every tutorial I found said to simply upload the .zip of the dream island/ backup island with JKSV into the device save section in ACNH. But this will not work or at least it would not for me no mater what I tried.
HOW TO USE DREAM ISLANDS/BACK UP FILES WITH JKSV - ACNH
If you are starting a fresh Island/ have no save file on your Switch, you need to play through to when you get your nook phone and can save the game.
Save your game and log off. Back up this save with (JKSV, Device - ACNH, - backup) and extract it to your computer. Make a copy as you will be overwriting this file.
Open the main.dat file of your fresh save island into NHSE, then open the main.dat dream island/backup of the other island you want in NHSE as well. (two instances)
Save/dump all of the files, acres, items, buildings, and if you want designs, flags, villagers etc. FROM the dream island/backup
Import all of these files into your fresh island save, acres, items, building locations, flags, designs etc.
I find you have to do the acres size first or your get an error that the acres do not match with uploading other files.
Save your fresh Island save as which ever you want, and then .zip the Villager0, etc. folder, the landname.dat, main.dat, and the mainHeader.dat into a .zip.
Upload this to your JKSV folder. GO to JKSV, I have been told it works in applet mode, but I have had issues with it crashing so i use full ram mode, or whatever its called (hold R when opening a app or game and it will launch hbrew)
Restore your newly made file with JKSV into: Device - ACNH
If there are other tutorials on this, I could not find them at all so hope this helps anyone.
Hello, I am brand new here. I am having trouble with ACNH restore files. I have refreshed my switch (a V1), made sure, atmosphere, HB, bootloader etc is fresh and updated. backed up my NAND, did an emummc generation and am running emummc cfw. I installed JKSV, loaded up my restore files/ island files that I want to load into the JKSV file folder.
I made a new user file, launched ACNH to get the save file to appear in JKSV.
Closed ACNH, went to JKSV in full ram mode. (though i read this should work in applet mode as well), scrolled to ACNH on the Device tab, located the restore file, hit restore, waited.
Closed down JKSV, launched ACNH and it will not load the save file I restored.
It continues to act as if its brand new and theres no save file and wants me to start again.
Am I missing a step here? I did read somewhere that you have to change the Island/playerID to match the profile save, but this was an old post and I could not find a way to even do this.
Any help would be wonderful, thank you in advanced.