Steps to Fix Yahoo Mail Sign in Problems
1. “Caps Lock” or “Num Lock” keys: Make sure that you have not toggled any of these keys on your keyboard.
2. Web Browser Autofill Settings: If you have configured your web browser to remember your Yahoo Mail login credentials and you have recently changed it, you will need to update the password in the Autofill Settings of your browser.
3. Unsupported Browser: Using an unsupported browser to access your Yahoo account can also cause sign-in problems. Try switching to a supported and up-to-date web browser to access your Yahoo account.
4. Someone Changed the Password for your Account: The sign-in error can also occur when some might have hacked your account and changed the password for it. In such a case, you can recover your password by resetting the password for it.