Click the menu button Fx57Menu and select Preferences.
   In the General panel, scroll down to the Firefox Updates section.
   Check Never check for updates (not recommended) and uncheck Automatically update search engines.
   Close the about:preferences page. Any changes you've made will automatically be saved.

Per Firefox guidance there is an option to toggle on an option that would not would not prompt to update. The option box though is not an option in preferences (See below). Did this option once exist, but it is no longer available and no one bothered to up date the trouble shoot guide? If so, why does it not still exist? Can it be brought back? If not, is there some backdoor way to shut it off? Thank you kindly Firefox occasionally checks to see if any updates are available for itself and for your search engines. To disable these checks: Click the menu button Fx57Menu and select Preferences. In the General panel, scroll down to the Firefox Updates section. Check Never check for updates (not recommended) and uncheck Automatically update search engines. Close the about:preferences page. Any changes you've made will automatically be saved.