I have multiple problems with upgrading Firefox from 49 to 61 The main one is horizontal disintegration of scrolling making pages unreadable Menus dropdown and right click are unreadable / missing or segmented Text addition to entry boxes is slow to appear (several seconds) or does not appear at all (blind text entry) Top bars and menu bars break irrationally across the screen Tabs may appear or not when created, sometimes they appear as a thick line to the right and can be clicked on ie they exist but are mostly hidden Things tried - Re-installing from Ubuntu Software Centre has given the best results - partial usability Disabling and removing all add-ons was no use whatsoever (done manually and using Firefox's refresh) Purging xul-ext-ubufox helped Removing a lot of data and using Bleachbit to purge cache and clean free space helped All hardware acceleration was unticked in Firefox Settings Multiple instances of Firefox reduced to one (this worked when my WIndoze Firefox was uprgraded to 52 - small memory notebook) Various about:config solutions were tried WHEN the entries were visible in the list including disabling Web3GL Now I have temporarily working solution. I say 'temporarily' because I am using it but any time today or tomorrow it could stop again If you have any other ideas, please let me know because I need the computer for work and I have lost so much time..... Seamus