It sounds like a glitch where the update didn't replace a program file, resulting in an inconsistent mix of files. If the problem occurs again, please try: '''Clean Reinstall''' We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent or alien code files). As described below, this process does not disturb your existing settings. It's not essential to uninstall Firefox, but you can if you like, saying No to any request about removing personal data. It only takes a few minutes. (A) Download a fresh installer for Firefox to a convenient location: https://www.mozilla.org/firefox/all/ (B) Exit out of Firefox (if applicable). ''If you use '''Microsoft Office''', please change your default browser to Internet Explorer before the next step.'' (C) Using Windows Explorer/My Computer (hold down the Windows key and press E), right-click > rename the program folder as follows (you might have one or both): C:\Program Files (x86)\Mozilla Firefox =to=> C:\Program Files (x86)\OldFirefox C:\Program Files\Mozilla Firefox =to=> C:\Program Files\OldFirefox (D) Run the installer you downloaded in step (A). It should automatically connect to your existing settings. Any improvement?

Thanks, doing (A) worked