Q: yahoo mail problem using firefox

I am currently running Mountain Lion and Firefox 44.0.2. Recently Yahoo Mail

changed their application signon to two screens; i.e. first enter the userid and

then the pw on the second screen.

Since changing their signon procedure I can no longer sign onto Yahoo Mail

using Firefox on the MAC. The pw screen just hangs after the pw is entered.

Does anyone have a suggestion as to what setting(s) I need to change in

Firefox to make Yahoo Mail work again.

TIA,

Ed