Can't add Google Account to OSX
This issue was plaguing me for a long-time and was really annoying.

I initially thought it was an issue with a random plist or other file hanging out in the Library/ folder and I tried deleting many of them to try and get to the bottom of this.

Eventually, I was tipped off to a Keychain issue by looking in Console, which with some Google'ing, led me to this post on Apple's forums.

Ultimately, I removed all of the following items in Keychain Access, retried adding the account in Internet Accounts, and everything worked well!



It sounds like it was only the com.apple.account.Google.oauth* tokens that had to be removed, but your mileage may vary.