Time and date are correct but I'm also getting this error. No internet.
EDIT: So after editing the options.json file with just regular old notepad as suggested above it didn't work initially but then the tinfoil error just stopped after messing with the menus a little. After two days I think I've finally squared away everything, now time to enjoy the fruits of my labor.
I'm getting this same message I am noob to this I have followed all the instructions I don't even have tinfoil installed but everytime I click on sx installer I get tinfoil. Io login error my switch is connected to the Internet did anyone ever find out what the problem is? I have just set sx os for the first time this the first time I have homebrewd my switch