Yes, there is. It's on page 3 of the Classic Theme Restorer "Tabs" options, aka uncheck "Close window with last visible tab", aka "about:config >> browser.tabs.closeWindowWithLastTab" if you don't use CTR.
Yes, there is. It's on page 3 of the Classic Theme Restorer "Tabs" options, aka uncheck "Close window with last visible tab", aka "about:config >> browser.tabs.closeWindowWithLastTab" if you don't use CTR.