I used to use Firefox as my default browser on my desktop iMac but uninstalled it a few weeks ago as I was having Flash Player problems and went back to Safari. For the last couple of days I have re-downloaded Firefox and although it installs to applications ok when I click on the icon it will not bring up the start page. I have set it as the default browser in both Firefox and Safari but still it won't open. It shows up in the menu bar at the top of the screen but whatever I set in preferences it won't open and I can't shut it down unless I use force quit.
I have uninstalled it and tried downloads from different sources but still have the same result.