I just bought a subscription to Office 365 and entered my email and password for my Microsoft account and the program is telling me that it doesn't recognize that account, which is the only MS account I have and so definitely
the one that I used to install the program for the trial period.
I've got it!!! I figured it out!
SO, Microsoft and it's password security gives you a random password for all of your Mac Apps. I have no clue why. So this means that it will not accept your usual password when registering applications such as Microsoft products; you need an "App Password."
BUT I figured out that if you use this app password with your Microsoft email instead of your usual account password, it is successful!
First, log onto your Microsoft account, go to the security & password tab. Scroll down to App passwords. You can create a new one to get one to solve this problem. Copy and paste!
Thanks, but no thanks, Microsoft Support.