The case is that I can login on http://icloud.com with my user and password, but when I try to connect the iCloud with my mac book pro is saying "An unknown error occured":

the error is shown when i try to login Here is my system information:

mac os description It was working just 3 days ago.

Now when I log in to my mac everything is just clean, even on Google Chrome all cache and sessions are lost.

  • Firstly, welcome to Ask Different! :) I hope you find this site to be a valuable resource. As for your question, can I ask how long you've been having this problem? Did this happen to coincide with anything else you've recently done?
    – Monomeeth
    Jun 28, 2018 at 12:31
  • It appears you have the Sierra background, but can you just confirm what of macOS you're running. Jun 28, 2018 at 13:54
  • Also: Does this occur in others users on other computer? Does this occur with other Apple ID's? Does this occur on other computers? Also can you try pressing the Sign Out button and then signing back in? Jun 28, 2018 at 13:56

2 Answers 2


Fixed by:

  1. Signing out (tried to login again but nothing)

  2. Reboot from terminal with -l:

    sudo -i
    reboot -l
  3. Signing in again.

and it worked for me.

  1. Backup all Files from ~/Library/Caches and delete the folder "Caches"
  2. Backup all Files from ~/Library/Application Support/iCloud and delete the folder "iCloud".
  3. Backup all Files from ~/Library/Preferences/ and delete the file "MobileMeAccounts.plist"

Restart and sign into iCloud. It helped me.

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