If you have that extension installed then you can also do the update check via the right-click context menu on the about:addons page.

hello, the same new version is also showing up on the addon homepage at https://addons.mozilla.org/firefox/addon/video-downloadhelper/versions/ so this notice is very likely genuine. however you can also use the auto-update that is built-into firefox - go to firefox > addons & click on the settings icon on the top right & choose check for updates..., then it should be picked up as well.

AFAIK then that is now the current 4.9.14 release (Feb 22) and all latest versions are the same and updating should work.

• https://addons.mozilla.org/en-US/firefox/addon/video-downloadhelper/