Yahoo help indicates security questions are no longer used. They suggest setting up your email address and phone number. If you are locked out, they will send a code to your phone device, and an email to help unlock your account.
Possible fixes
Restart your Web browser. Clear your Web browser's cache. Make sure you're using a supported Web browser and operating system (OS). Sign out of all devices and sign back into Yahoo Mail to see if the error is gone.
Turn in a repair ticket
Go to att.com/repair and select Home Phone.
Enter your home phone number and select Continue.
Tell us about the problem you're having, then select Continue.
Review any troubleshooting steps to see if you can fix it yourself.
Follow the prompts to submit your ticket.
Uninstall Norton Security Online/Norton Security Suite for PC
From the start menu, click the Control Panel.
Select Programs.
Click on Program and Features.
In the list of currently installed programs, select the Norton Security product, and then click Uninstall or Remove.
If the User Account Control window appears, click Yes.
Follow the on-screen instructions to select your uninstall preference.
Norton uninstaller will run and complete.
Restart your computer.
