I've signed in and out of my Google account in Chrome and Safari but I keep getting this message. I've also tried deleting gmail from my accounts in preferences, mail and calendar. When I go to add it back I get the same message.
Google requires completing authentication in your web browser.
After authentication, setup will continue in Internet Accounts.
Mac mini, macOS 10.15
As of May 30, Google has done what Apple did 5 years ago. It is now requiring 2 factor authentication and app specific passwords for "less secure apps" such as Mac Mail and Apple Mail.
You have to go to your Google account, start 2 factor authentication, and get your app specific passwords to use gmail on your older mac or iPhone.
Or just do what I did: When Apple did it I just forwarded my iCloud email to gmail. So now I'm just going to forward my gmail to my iCloud email account. (This can be set up in Webmail).
What a hassle
As of May 30, Google has done what Apple did 5 years ago. It is now requiring 2 factor authentication and app specific passwords for "less secure apps" such as Mac Mail and Apple Mail.
You have to go to your Google account, start 2 factor authentication, and get your app specific passwords to use gmail on your older mac or iPhone.
Or just do what I did: When Apple did it I just forwarded my iCloud email to gmail. So now I'm just going to forward my gmail to my iCloud email account. (This can be set up in Webmail).
What a hassle
Was the authentication successful or do you get any error?
Are you able to access your Gmail from the default(Safari) web browser?
Have you tried safe for troubleshooting?
How to use safe mode on your Mac - Apple Support
Note: Safe mode prevents your Mac from loading certain software as it starts up, including login items, system extensions not required by macOS, and fonts not installed by macOS. It also does a basic check of your startup disk, similar to using First Aid in Disk Utility. And it deletes some system caches, including font caches and the kernel cache, which are automatically created again as needed.
I do get a Safari window message to authenticate which I've done several times. Doesn't work.
No, authenticating my gmail/google account does not work. I still can't add gmail to my apple mail. Signing in and out of my gmail/google account from both browsers, Chrome and Safari, works fine. The problem is adding my Google account to Internet Accounts in Preferences. Actually i should say re-add. I removed it and tried to re-add it as suggested but I still get the same message I got before I removed it:
Google requires completing authentication in your web browser.
After authentication, setup will continue in Internet Accounts.
I've decided to use gmail forwarding to my apple mail temporarily until I can figure this out. I'm going to hold off on safe mode unless there are no other suggestions today.
You can set up 2 factor authorization in your Google Account. That means that you would need a 2nd device to set it up, and to get a code when you log in from an unknown device. Same as Apple. On the other hand, I was able to set it up using a land-line, and then it let me generate 10 "permanent codes" that you can download and enter to log in to your account without needing the other device.
Once that is done, you can set up app specific passwords (same as Apple) and enter them in MacMail. You keychain will remember them and you don't need to re-enter them, but absolutely write them down!!!!
Also of note: this will let you use Gmail in Mac mail as IMAP ONLY. You still will not be able to use gmail as POP.
Good luck.
You may need to quit safari and apple mail, then start to add in Internet Accounts.
You should get a safari window prompt to login/authenticate. (Are you able to get this window?)
I've done that several times. Same message everytime.
If you don't get a safari window prompt to authenticate, suggest you to try safe mode.
ok
Gmail
