Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Thank you so much for the Libre Office idea, I downloaded version 7.4, a slightly newer one, and it works on my Mac. High Sierra. I guess that is what I am going to have to do, going forward. It will be a learning curve, I have used Word since it first came out in the late 80s, and it's a shame I need to change now, but if my legitimate copy of Office no longer authenticates, I have no choice.
However, having spent so much money on perpetual licenses in the past dictates that I cannot just leave a computer behind that still works fine, and I still have working copies of Adobe Creative Suite on it I bought before everything went to a subscription. I love it and want to keep using it, so older OS is the way to do it.