Every day when I come back to my mac and firefox is open, it will not respond to any new web address. I can put in any web site and it resolves the full page name, but does not open any site. I have to close firefox completely, which is a pain when I have multiple pages open. It does not matter if I have one or tabs in use, I am forced to close out of firefox completely in order for it to work again. This has been going on for years for me with firefox through multiple versions, multiple MacOS, and multiple Mac systems.