several times my computer has crashed. During normal times when I reopen Firefox it will restore the last session. Also if Firefox itself has a problem, it might restore. But on several occasssions the computer has crashed and it has not restored. As I opened several tabs long ago it is next to impossible to find the tabs that were open. Many of these tabs were extremely critical items of things that I need to do. Now I am not able to finish these tasks. This may even result in me breaking the law, e.g. important government documents I needed to fill, or loosing significant amounts of money, e.g. online invoice forms, also not being able to finish certain work tasks and then to discipline. It is hard to overestimate how important it is to know what tabs were open.
It is a simple task to store the urls in a text document. That way at least if Firefox didn't restore, the addresses could be easily obtained. Another idea would be that every time that a session is restored, those pages are added to history. That way if one needs to see what pages were open they don't have to go through several days, or sometimes weeks or months, of history.
Please, please, please do this. In the meantime, I will, with a heavy heart, explore other browser options