Mac can't Connect to iCloud

The features facilitated through the iCloud service have become one of the core components of Apple's ecosystem. As a result, any disruption in the normal functioning of iCloud could have serious consequences. Even more so if the user's device cannot connect to iCloud at all. If you are experiencing this problem on a Mac, try the solutions outlined below.

Sign-In to iCloud

1. Go to the Apple menu and choose 'System Preferences.'
2. Click on 'AppleID.' On older macOS versions, choose the iCloud pane. 
3. Go to 'Overview' and click the 'Sign Out' button.
4. Follow the same steps but this time when you click on 'AppleID' you will have to input your AppleID credentials. 
5. After logging in again, check if you now have a connection to iCloud.

Remove Cache Files and Temporary Data

1. Open Finder, select the Go menu and then choose 'Go to Folder.'
2. Enter the ~/Library/Application Support/iCloud/Accounts/ path and press the 'Go' button.
3. Try the files located in the destination to the Dekstop.
4. Restart the Mac and check if you can successfully connect to iCloud.
5. If the problem persists, follow steps 1 and 2 but this time enter the ~/Library/Preferences/ destination.
6.  Locate the com.apple.systempreferences.plist file and move it to the Desktop.
7. Restart the Mac

Another option involves opening the ~/Library/Keychain/ location and moving its contents to the Desktop. Again, restart the Mac before trying to connect to iCloud once more. 

Reboot in Safe Mode

To check for any software interference that might be causing the issue, start your Mac in Safe mode. The exact method depends on your Mac model.

For Apple silicon-based Macs:

1. Shut down the Mac.
2. Press and hold the power button.
3. When the startup options appear, select a startup disk.
4. Press and hold the Shift key on your keyboard and click 'Continue in Safe Mode.'

For other Mac models:

1. Shut down the Mac.
2. While pressing the Shift key, start the Mac.
3. When you see the login window, release the Shift key.
4. Proceed to log in as normal.