I have sip disabled, 5,1 firmware mounted on desktop. Then I try to open the Firmware updater and it says it requires an internet connection. I just can't fix the internet connection. I tried connecting using bluetooth PAN to my macbook pro to get internet access and that didn't work either. This is a recently purchased 4,1. I have a freshly installed El Cap at 10.11.6. How can I flash without using internet? Alternatively, how can i get the ethernet or wifi working? Bluetooth is working currently, but the option to connect to another Bluetooth PAN device for internet access is grayed out stating that there aren't any other devices available...but there are. My MBP is running catalina, if that makes a difference, and i set it up in sharing is sys prefs, sharing wifi over bluetooth.