Lolu chungechunge lwabekwa kunqolobane. Uyacelwa ubuze umbuzo omusha uma udinga usizo.
Tree tabs duplicates the menu bar tabs. Remove the menu bar tabs. This question isn't answered https://support.mozilla.org/en-US/questions/1184674
Tree tabs allows the tabs to be tree styled on left or right of the screen. Firefox newer version now has these tabs on menu bar on top and on the tree tab, which is a real eye sore.