Posted in case it helps someone else.
One of my website clients asked for help with one of their Mac OS X laptops, which had suddenly stopped connecting to their wifi network. The wifi connection seemed to be demanding a WPA enterprise username and password, despite being set up as WPA2 personal, which only needs a password.
In the end, the cause was a combination of a new modem/router from the cable company, and an old version of Mac OS X (10.7.5). I had to go to the app store to download El Capitan, since you can’t update from 10.7.5 to High Sierra directly, but after installing it the laptop could connect to the WPA2 personal wifi network on the new modem/router. It’s now been updated to High Sierra, and the company reminded to install the updates they get a little more regularly…
