I did not know I had two windows open. One of the issues I have had with FF is that if there are two open and I close the main one (with all my tabs open) first, there is no possibility to restore that session. If I close the "daughter" window, no option to restore appears when I open FF again. So I'm stuck, unable to restore. I saw an instruction to "replace some file with another, found in the profile folder", but I've no idea where a profile folder might be found. Additionally, now that I closed the daughter window and tried to reopen FF to see if there is a session restore option on either the menu or the library button, now I have had two sessions open and will no longer find (AFAIK) a copy of a session older than two sessions existent. This happens now and then, and I wish I didn't get caught this way. Now what, please?