Rated 5 out of 5 stars

Από τον/την Χρήστης Firefox 39d95a στις Δεκ. 14, 2017 · μόνιμος σύνδεσμος

This excellent add-on fills a big lack of Firefox for the backups and the restorations of the tabs.
Not useful only in case of problems but for example it allows to manage profiles of tabs by theme.