If needed, press and hold both the Power (On / Off) button and the Home button (which is located right below the screen) together for at least 10 seconds, until the Apple logo appears, then wait a bit, then check.
- If that does not work, open Settings app icon, then select option Mail, Contacts, Calendars, then tap on the Yahoo account, if any, then tap on Delete Account and confirm to delete it for now. Then tap on option Add Account, then tap on option Yahoo, then enter your yahoo account information, and check.
- If there is issue with your Apple ID account password, click on the Apple website below:
, then click on Continue at bottom, and follow the instructions there in order to reset your Apple account password, and check.
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