Problem: When I try to sign in, I get a spinner forever saying "Loading..."
Details: I installed Office 365 Personal on a Mac. When I start Word, it asks for my email, which I entered successfully. But then the window shows just the spinner and "Loading..." and never asks for the password. I tried rebooting. I tried Word and Excel. I can log in successfully with this id on office.com on the same computer, so the network and account work. I tried Ethernet (which is very slow) and WiFi. No error messages show up, just the spinner for minutes. The only unusual factor I can think of is the Mac previously had Office 2004 installed.
Any suggestions? I'm kind of stuck. I searched the web for solutions but didn't come across anything that helped.