Can't login with Google using Internet Accounts

I configured my Google account on El Capitan (OS X 10.11.2) using Internet Accounts and it worked fine for a while. However, after a restart the system asked again for the password and 2-factor authentication code, which I provided, but then I get stuck in the following window after entering my password and code:

In the above window, if I hit Cancel and then try to select anything in the Google account I get the message "Unable to verify account name or password."

If I delete the account and add it again I'm asked for my password and 2-factor authentication code, but after providing them I get stuck in the following window - notice that the Done button turned grey after pressing it, and the dialog never closed after that:

I already tried starting my system in safe mode, with the same results. What's happening? Any help will be greatly appreciated!

1. Open Keychain Access.
2. Make sure "login" is selected in the upper left under "Keychains" and manually delete every entry that is associated with Google (any entry with Google in the name, I deleted). Specifically, the entry "com.apple.account.Google.oauth-token" is the one to delete.
3. Go back to Internet Accounts and add your Google account.

This just randomly started happening to me on Sierra (macOS 10.12.3).

I removed my Google account from Internet Accounts in macOS so I could re-add it again. It brought up the login process and then hung at the end with no spinning wheel.

However, upon enabling "Access for less secure apps" in my Google preferences, everything started working again.

I've been struggling with this issue as well for a few days on OS X 0.11.4, before that it worked flawlessly. In my case I went to Keychains > Login > Passwords > Google and removed all the security tokens.

Now I can add Google accounts again.