Whatever doest this nice little error message mean??

I’ve been trying to log in to this wonderful application, and I’m getting super frustrated. I moved from altsotre to get rid of the rather annoying “data couldn’t be read because it isn’t in the correct format” error, and now sidestore started also showing it. I beg someone to help me. Localdevvpn is running, changed the tunnel and the deviceid to whatever was in an earlier post but it still doesn’t work.