AOL has changed the requirement and require additional work. See this information.
Yahoo Mail, in common with many other Mail providers (such as AOL, Google and Microsoft) has switched to using App Specific Passwords when using anything other than their own email client Apps. Your recent software update has triggered an account settings update.
If you need to generate an App Specific Password, you’ll need to log-in to your Mail Providers account management webpage - using a web browser - and generate the Password from the appropriate account security page.
More information about AOL’s App Specific Passwords can be found here:
https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in?guccounter=1