iCloud account details could not be opened

Hello neoflyer,

After reviewing your post, it seems like there is trouble connecting to iCloud. We would recommend you use this article to help troubleshoot the issue. If you are not able to connect to iCloud, other services may not be working also.

If you can't connect or sign in to iCloud

Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.

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if you can sign with Apple ID and password at www.icloud.com and appleid.apple.com with credentials and not from Mac system preferences the user account is corrupted .

Click on finder > take cursor on top menu bar > Go > hold option key and click on library from the preferences folder drag and drop com.apple.system preferences .plist to the desktop , restart the Mac and again open safari browser for few minutes , the .plist will be again recreated .

You can create a new test user account and monitor that accounts details can be clicked in the new test user account , but in it Apple ID and password has to be signed in what is the version of Mac used , use safe mode also https://support.apple.com/en-us/HT201262