server says unauthorized yahoo mail and ask to put in the password again, but it doesn't work

Server says unauthorized with yahoo mail and it asks to put in your password again which I did but it won’t accept it even though I’m putting the right one in.

I found a post back along which said to uncheck the CalDAV & CardDAV in account settings which does cure the problem, however you cannot then see contacts in the contacts folder.

Does anyone know how to fix this annoying issue?