Can’t log into iCloud on iMac

I had exactly this problem, and had several months of communication with Apple Support, trying everything they could think of. Finally, we found there problem - it was that the proper keychain file wasn’t right. They had me go to my users/<my home folder>/library/keychains folder, select all the files and put them in a new folder (just using the default label, New Folder With Items), then log out (under the Apple menu) and then log back in again.

While watching this keychains folder during the log in, I could see a number of new files being created, and then I was able to have everything working again! (Note that this Library folder is normally hidden from view, so if you can’t find it, you will need to change that. Here’s some guidelines: https://soundsupport.biz/2016/07/17/how-to-make-your-library-folder-visible/)

You mean to say enter in user library by clicking on Go > Go to folder and type ~/Library/Keychain then create a new folder on the desktop ( then select all contents of keychain folder use command and A keys ) , copy them ( command and C ) and paste into the folder ( command and V ) .

I have done this experiment the only draw back is in user library > preferences folder > all .plist will be in disturbed they will move up and down and not will be in alphabetical order , sometimes the entire keychain folder is dragged and dropped on the desktop , restarting the machine and opening safari for few minutes ( browsing is done on it ) and after that a new keychain folder is automatically created .

But we users must not delete it because without the help of apple support the .plists can not be arranged in alphabetical order .

In op case I don't know when the iCloud Keychain was created is he/she having iCloud verification code in records , as deleting the login keychain from keychain is to be done or by going to keychain access ( with the help of spotlight ) , then open keychain access preferences ( can use command and comma ) and click on reset my default keychain , it will delete both iCloud Keychain and login keychain and a new keychain will be created in user library > keychain and the old corrupted keychain will be moved aside and will be deactivated in user library > at the same location > keychain .

But , the user must have all web mail addresses , iCloud address Apple ID address and respective passwords , I cloud verification code , if airport express is configured ( the wireless network password that is kept same as base station password ) as all of them will get emptied , before following the steps .

And a expertise can set iCloud Keychain " only " with the help of iCloud verification code , I have posted some user tip in the Mac OS High Sierra or Mac OS Sierra group for this .

See this article Keychain for Mac: If you’re asked frequently to unlock your keychain

Well, they didn’t have me create a new folder on the desktop and copy/paste items; I just selected all items in the keychains folder and used the Finder’s File menu to select ’New Folder with selection’. This put everything in a folder in my keychains folder. Then logged out and back in, and that resolved the problems I had.

It may have solved for you , but in my case when keychain was corrupted it didn't helped , of course apple support helped to reset the .plist alphabetically ( logs and disk images were send ) and took 7 to 8 days with the help of them .

See these two articles Sign in with your Apple ID - Apple Support

Set up iCloud - Apple Support

Read the steps in the article Two-factor authentication for Apple ID - Apple Support

Thank you!!! I was at my wits end trying to trouble shoot this🙂