I keep lots of Firefox windows open with varying amounts of tabs open in each. I've used the Undo Close Tab command more times than I can count when I hit the wrong button accidentally within a window. Unfortunately I accidentally hit the close button on my most important window instead of the tab in the next window over and I can't figure out how to get my window back. I'm on a Windows 10 64 bit computer running Firefox version 64. A friend of mine pointed out that I wouldn't be having this problem if I bookmarked every website I wanted to go to instead of just keeping them all open all the time, and I guess she has a point, but aside from being a bit lazy, it's also about having found a particular spot within the website that I want to be able to get back to, and you can't keep bookmarking all of those. I'd appreciate any help anyone can come up with to help me find some or all of the tabs I lost in that window. Thank you very much for trying!