Those add-ons were considered legacy add-ons, and are no longer supported, so they were removed.

Legacy Extensions were for the old Firefox 56.0 and earlier including the EOL Firefox 52.9.0esr. They will not work on Firefox 57.0 and later including current Fx 64.0 Release.

Some of the legacy extensions that worked on Firefox may still be listed on https://addons.thunderbird.net/seamonkey/

James said

Legacy Extensions were for the old Firefox 56.0 and earlier including the EOL Firefox 52.9.0esr. They will not work on Firefox 57.0 and later including current Fx 64.0 Release. Some of the legacy extensions that worked on Firefox may still be listed on https://addons.thunderbird.net/seamonkey/

Tyler Downer said

Those add-ons were considered legacy add-ons, and are no longer supported, so they were removed.

yeah i know, that's why i'm using firefox portable v45 because my firefox 64 not working with it

does anyone know related addons ? https://www.ghacks.net/2011/06/19/saveall-add-on-saves-all-firefox-tabs/

oh i'm just using archive.org, worked extension for portable firefox :)

If one continues to use outdated firefox and legacy apps no one can stop you on here as help will be limited. So be warned your asking for Browser and Legacy apps security holes and if problem arrive - firefox forum will not be able to assist with any help because of it.

For future reference, to save all Firefox tabs, take a look at the new session-related extensions, such as Tab Session Manager or Session Sync.