Ctrl-W closed all tabs as if I pressed Alt-F4
Like the title already explains. I hit Ctrl-W and the entire firefox window with multiple tabs disappeared. Had to reopen it and restore session.
Alle svar (3)
It should be noted that I cannot reproduce the affect, it just happens some times. Like just now, hence this post. Also should be noted, I have been using Ctrl-W, Alt-F4, Ctrl-Alt-Del and ANSI free style for ... about 30 years.
Maybe you accidentally pressed the Shift key as well as Ctrl+Shift+W is the shortcut to close a window. See Windows & Tabs:
The same used to happen here intermittently. I think it was because my OS had ctl+w as the shortcut to close a window; perhaps you have the same. I avoid using that shortcut always because of the conflict.