I read the responses that were posted as of DEC 16. Thanks @lllaass, @dialabrain, @P.Philips, and @ku4hx for your replies.
I tried @lllaass' suggestion first: Check the app store. This was the first reply and it was straight-forward. It worked. Well, I think it was the reason why I was finally able to upgrade. Keep reading for my explanation, as well as my bumpy experience...
1 - "Finding Update" took about 10 minutes. I cancelled and restarted the download. So i did this step twice. The second time took about 10 minutes, too.
2 - The download finally started:
3 - A message appears stating that authorization is required to install the package. I thought by clicking [OK], i would be prompted to enter my password. Instead, I’m returned to this window:
4 - I re-tried installing from the app store again and got the installation window:
5 - It got stuck at 52% for a long time (at least 20 mins)
I cancelled and re-tried the installation from the app store again.
It pretty quickly went back to the 52% window and got stuck again.
6 - I cancelled it again.
When the "Software Update" window appeared again, it stated 12.1 is available:
At this point, I don't know if what I did got me to this state *OR* if the update was finally made available to me. I usually get the updates the evening of release day. I've not waited 48 hours.
7 - I clicked [Update Now] and the rest was normal behavior. The update was done in about 25 mins. I stepped away, so the actually time was probably less.
Done!
