Q: Cannot login to Mac after linking icloud password

This gets interesting - but at least it had a happy ending.

To explain the problem fully (and to help anyone who ends up in similar situation) I had two user accounts setup on my Mac. Me as admin and my wife as standard user. My kids somehow figured out my password so I decided to change my password. When I changed the password, Apple offered me to use my AppleID password (which incidentally was the same as my login password). So I linked the two together. And then I tried changing my Apple ID password. My apple ID was ****@yahoo.com - an account I never use. My icloud ID was set up with my ***@msn.com address - an account I prefer to use.

When I logged into AppleID website, I was offered to use the same email address for both my AppleID and iCloudID - and I thought why not. So I selected my ***@msn.com account as my new AppleID and CloudID. Then I changed the password. And then I had to leave my Mac for a while (which locked the screen) and when I tried logging back in - Mac would not accept my password.

I guess that was because the Mac still thought my AppleID was ***@yahoo.com whereas in the background, that ID had been replaced by ***@msn.com.

Anyway, I called Apple Support... They got me to login using Cmd+R and use resetpassword command on my ID. Tried logging in again, didn't work. They suggested I take to an apple store. Which I did.

Apple store tried the same thing... nada... They were also unable to do anything else with is as I had FireVault activated as well. They suggested a backup of data and re-install to correct the issue. I, thank goodness, ignored their advice and brought my Mac home.

Logged in using my wife's account and tried enabling root access using dsenableroot. The command failed. So I rebooted using Cmd+R and reset the root password. This time I was presented with the option to login as Other. I used root as ID and my new root password. It let me in. I went into users and saw that my admin user account was indeed linked to ****@yahoo.com email address. Unlinked it. Which allowed me to login.

Then I had to signout of iCloud using my admin login and then re-login using my new ***@msn.com icloud ID. All is working now.

Moral of the story... (1) iCloud and AppleIDs are a gigantic mess... (2) Don't assume that Apple Geniuses necessarily know the best. I mean come on - when did Geeks ever look that cool