When installing a NSP, sometimes i get "please turn airplane mode off when appropriate for your surroundings" code. I turned it off so i wont connect to the servers and other nsp's work fine. Any advice? im using goldleaf & goldtree 0.5
copy and paste the file to your sd card and install from there (if the files are too big split them up and tag off archive in folder properties of the split game) .
also 90dns is just a dns server so it's just changing some internet settings.
try to connect to your internet but put in and save an incorrect password then change to dns to 90dns, then change the password to the correct one (so you only are connected with 90dns on first)
You need to dump your prod.keys and also have patches added before you install a nsp or it wont be decrypted properly. Also if a newer game might require newer keys, you might have to redump your keys if its been a few FWs since you last dumped them.