Try to rename secmod.db (secmod.db.old) and cert8.db (cert8.db.old) files in the Firefox Profile Folder in case there is a problem with the files.<br /> Firefox will create new files. * https://support.mozilla.org/kb/Could+not+initialize+the+browser+security+component ---- Create a new profile as a test to check if your current profile is causing the problems. See "Basic Troubleshooting: Make a new profile": *https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems. If that new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files. See: *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox