When using the new Yahoo email version and Firefox 42 I can log in to my emails but can only get as far as the Inbox. I can see the list of emails but cannot open them, delete them or any other function. I cannot open any other folder and there are no drop down menus to log out or open anything like Options etc. If I click on any of the buttons or try an access the drop down menu nothing happens. It is as though the page has frozen, although I know it hasn't because I can leave the page and go to any other website or part of the yahoo network. I get this with all Yahoo accounts including Talk 21. The only way to overcome the "freeze" is to load Yahoo classic. I can then continue to use my email. If I then switch back to the new version, it works ok while I maintain the cookies in my browser. If I clear them, then I'm back to having to load classic again. It is as though a cookie is not coming through when accessing the new yahoo email in Firefox. This does not happen when using other browsers i.e. Safari. I have tried reinstalling Firefox, I always clear my cache each time I use my computer and I have tried using a different computer from another location. This happens with both mac and Windows computers from any location.