I've got two new GNex, and this morning, I decided to just turn one on without the SIM card installed and joined it to my local wifi Internet. Everything connected fine, I was able to surf the net on the GNex browser. So I decided to try the USB tethering option. I connected the stock USB charging cable that came with the phone to my laptop and the GNEx, and enabled the USB tethering option. The box checked green with no subscription prompts. I pulled the LAN cable from my laptop and to my surprise, I was still able to surf the Internet.
In the meantime, the GNex received a prompt for a system update. I decided to click yes. So I disconnected the USB cable and just let the phone do it's update.
After the reboot, I decided to go ahead and just activate my phone. So I powered it back off and installed the SIM card.
Long story short, turns out the SIM card I had was somehow set to retired status because I didn't activate my phone in time...
So now I go back to just using my phone via WIFI and try the USB tethering option, I get an Error message that says "Either MDN or ICCID is not Valid"
Why doesn't it work anymore? Is it the system update that prevented this or the retired non working SIM card?
Current build on the Phone after update is ICL53F.