Setting up FF on an OSX Sierra computer. The icon is in the toolbar & allows me to set Prefs. But in about:addons it says "Install cancelled". I know there are issues w/ having to fix Sierra to allow me control over my property (installing "any" app). I had to right-click the FF .dmg & "open" instead of clicking on the dmg file. Have not found a Terminal command that works to give me the "from anywhere" option in OSX Prefs. Also, in FF "find more extentions" I cannot tap a couple times to SELECT text in the box & then delete it, so I can type something else. Having to awkwardly press & drag to select the text. Is the FF behavior or OSX Sierra effing this gesture up? This is gonna take hours & hours to get all the addons installed... Can I copy an addon file from another install of FF on another computer & drop it into the .profile on this new computer?