Hi, Please try this: In Firefox: '''Help''' ('''Alt''' + '''H''') > '''Troubleshooting Information''' > '''Open Containing Folder'''. This opens your current [http://kb.mozillazine.org/Profile_folder_-_Firefox Firefox Profile Folder & Files]. Exit Firefox and delete the '''extensions''' folder and also the files named '''extensions.*'''. From the old Firefox folder copy only the '''extensions''' folder to this folder and any other folder and files bearing an extension's name (you can see this by doing a quick comparison of the two folders; most of the extra files/folders will have the extension name) and start Firefox. Firefox will open several tabs for the approval of the newly discovered extensions. Enable (tick) on all the tabs and click '''Continue''', but click '''Restart Firefox''' only in the last tab. Firefox will automatically start and hopefully you'll have all the previous extensions back.