I recently disabled a couple of extensions that could be used to download video etc from Youtube. I believe the extensions were Easy Youtube Video Downloader Express and Video DownloadHelper. Since disabling the extensions the keyboard shortcuts that you can use in Youtube to control video playback no longer work and functions e.g. sound levels that could be adjusted by using the mouse cursor also fail to work. It seems to me that the keyboard and mouse mapping has gone wrong for Youtube but it is fine for all other websites. I do not get any error messages, just an inability to control video or sound using the keyboard or mouse. As Youtube works fine with other browers I performed a complete reset of Firefox, version 96.0.3, as I thought that that would reset any error that might have occured when the extensions were disabled. I have reinstated 3 other extensions but at this time have not installed the Youtube ones again. The keyboard mapping and mouse cursor problems still exist when I try use use Youtube through my now reset copy of Firefox. Please could anyone offer a solution that would get my keyboard working correctly again with Youtube through Firefox? Nigel