cannot sign out from iCloud on iMac

My problem was due to changing my Apple ID username. It is suggested that you sign out of icloudon all apple devices before changing your username to prevent this sign out problem.

I had to call Apple Support on this one. The solution which worked was:

1. Go to System Preferences > Users and Groups > unlock padlock > click plus sign > create new user not as "standard" but as administrator (we just used "test" for name and every other field)

2. Log out of your account

3. Log in as new "test" user

4. Sign up for icloud using new icloud username and password, then go to system preferences> icloud and unclick the "find my mac" option in icloud preferences. Log out.

5. Sign in to your usual profile/user, go to icloud and sign in using new icloud name.

(This has something to do with the find my mac program which links a profile to serial numbers of the devices.)

Is this what you are doing?

What happens when you click 'sign Out'?

I can't sign out of iCloud on my MacBook Air. It duplicated all of my notes and now refuses to sign out of iCloud.

i had the same problem...i first unlinked my icloud acct from my user id (under users in system pref) (and i dont know if this helped or not) because...i then unmarked all of the items contacts, notes, etc on the icloud acct, it made it inactive...BUT when it asks you if you want to keep the contacts on the computer say NO... then i hit sign out...and it worked!

i hope this helps

Same problem here. I told it not to save contacts and then it worked ok.

I've the same problem. I also tried to first unmark all options in iCloud system preferences, told to delete all and Sign Out afterwards. But sign out still does not work it hangs for ever telling me "signing out.." and task is using 99.9% CPU!

Did anyone find a solution to this?

I had the same problem, I tried to uncheck all options then sign out and it hung for a few minutes then said could not sign out. Try disabling etc. and try again. I noticed there was a details button next to my Kechain option. I clicked on the details and allowed my macbook to use the keychain by typing in my password to approve it. I then unchecked the keychain box again and hit sign out and it worked for me.

Same problem here. I have no idea how to fix this.

I had this same problem and the issue was with find iphone. Once I was able to disconnect from that, I was able to log out. Maybe this will help some.

Snap. iCloud works ok my macbook, syncing is painfully slow on new iPhone 6S Plus but it's frozen on my Mac. Can't sign out, says "not available" ??!

on my iMac iCloud tells me none of my devices are ok to verify keychain. Bizarre since they have done only the other week when I upgraded to el capitan. I've checked all the settings - they are all fine to permit verification for other devices - but the setting doesn't change so I'm stuck?

I had this problem as well. Couldn`t sign out from iCloud. This was because of keychain didn`t let me. The solution in the end was fairly simple. Are you ready?

I mean are you really ready for it? Ok here it is..

Turn off the internet connection from the device. When offline you should have no problem signing out.

It seems that as long as your devices are "communicating" with each other signing out from one device is not possible, especially when all the data between the devices/ iCloud accounts does not match.

I know I`m almost four years late from the original question, but I hope this will be at least of some help for those to face the same issue in the future.

That was surprisingly easy and very helpful. Thanks!