Hi, Please check if this happens in [https://support.mozilla.com/en-US/kb/Safe%20Mode Safe Mode]. [http://kb.mozillazine.org/Problematic_extensions Problematic Extensions] [https://support.mozilla.com/en-US/kb/Troubleshooting%20extensions%20and%20themes Troubleshooting Extensions and Themes] [http://support.mozilla.com/en-US/kb/Uninstalling+add-ons Uninstalling Add-ons] [http://kb.mozillazine.org/Uninstalling_toolbars Uninstalling Toolbars]

See also: *http://kb.mozillazine.org/File_types_and_download_actions *https://support.mozilla.org/kb/Managing+file+types ---- 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