Updated April 20th, 2020.
Microsoft Office 365 can get stuck when you try to activate it. The installation goes perfectly, you see a screen asking you to sign in, you put in your email address (or possibly your phone number or Skype address), and click Next.
You’re probably expecting the next box to show something asking for your password. Instead, you get this:
It doesn’t matter how long you wait– you’ll still be “loading.”
So, what should you do? Should you try reinstalling? No. Should you wait a little longer? No. What you should do is type your password anyway, even though there’s no place to type it, and then hit Return. Do that, and you’ll soon see this:
In a minute or two you’ll see this, signifying successful sign-in:
How cool is that?
Note: this problem only seems to occur with older versions of the macOS, from El Capitan (10.11) on back. It could be that the version of Office 365 that runs on 10.11 and 10.10 has this issue and that the “regular” version does not. Regardless, now you know the fix!