non-functioning Ethernet port - posted solution NOT WORKING

All of a sudden my Ethernet connector on the iMac stopped working. It's NOT the cable, as I plugged it into a different computer and the other computer connected with no problem. I did the fix posted on the mac support pages trying to update the Incompatible Kernel Extension Configuration Data. The support post says to update it to version 3.8 something, but mine is version 2.13! I did the fix explicitly four times, and I still have no Ethernet connection. Wifi is fine. Yes, I restarted everything. Nada. HELP!!!

I'm running Mac v10.11.6