The computer industry wants to drop passwords, so they are adopting two-factor authentication. This is a popular security feature introduced to add another layer of security to your accounts. It means you need to have your mobile to access such things as emails.
Since I have a smart house, I had to use my mobile to access my TV when activated. So I turned it off, as have many people I know.
I think it sucks, but its supporters say it would suck more if my identity were stolen. Well, you make your mind up as it is your call currently.
The immediate problem is that many of you use our software to access your email directly. It saves a lot of time. It also allows their POS Software to do many functions automatically.
To keep it working, you need to activate the App password.
This will change depending on what you are using, but in Gmail, it works like this.
First, pick a long and complex password, and cut and paste it in at the marked yellow area above.
Now go into options in your Point of Sale Software.
Now enter that long and challenging password where the yellow marker is shown below.
Save that, and the problem is solved.