Firefox is the most flexible browser you can install and use on your computer. It is always upgraded, easily customizable and full of add-ons you can choose to satisfy all your needs but sometimes, after an upgrade it crashes and does not run. Today, in our Linux Page (in Spanish) we have added a brief post about solving this problem. First of all, start Firefox in its Safe Mode (open Terminal and then type: firefox -safe-mode or if you prefer Alt+F2 and then type as described before). Immediately you will see a menu window with five different options. Click on the button which allows you to “Disable all the add-ons” and you will able to launch Firefox. This happens because some add-ons are not compatible with the new version of Firefox. To completely solve the matter you have to separately enable each add-ons and restart the browser after having added any single add-ons. In this way, you will be able to understand which is the “guilty add-ons”. Useful!