Mozilla Firefox Help

This article describes what to do if Firefox doesn't open when you click the Firefox icon. If you get a message you can dismiss (e.g.  "TypeError: Components.classes['@ ... ;1'] is undefined" ,  "onload error TypeError: ..." ,  "Exc in ev handl: ..." ) and can open Firefox, see Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems. If Firefox starts but won't load any websites, see Websites don't load - troubleshoot and fix error messages. The   Refresh Firefox feature   can fix many issues by restoring Firefox to its default state while saving your essential information. Consider using it before going through a lengthy troubleshooting process. The   Firefox Safe Mode   window includes a Refresh Firefox option. You can start Firefox in Safe Mode by   holding down the  shift  key while starting Firefox.    Mozilla Firefox Help Specific error messages Mozilla Crash Report...

Firefox users would do well to upgrade to the browser’s latest release if they want to keep their computers safe from compromise.  Mozilla Firefox Help Released on Monday, Firefox 58.0.1 contains one but very important security fix that plugs a vulnerability arising from insufficient sanitization of HTML fragments in chrome-privileged documents. (In this context, chrome is not the popular Google browser, but a component of Firefox.) The vulnerability (CVE-2018-5124) is considered critical because a successful exploit could allow the attacker to execute arbitrary code with the privileges of the user. And if the user has elevated privileges, the attacker could compromise the system completely. Another reason for such a classification is that exploitation can be triggered with just a bit of clever social engineering. “An attacker could exploit the vulnerability by persuading a user to access a link or file that submits malicious input to the affected software,” Cisco explain...