Apologies for hijacking your thread AOG, but the version number leapt out at me. Version 40 for a browser that has been around for 12 years is crazy. Safari, which is also 12 years old is on version 8.
I rarely use Firefox except for testing my own website creations on multiple browsers and EVERY time I do open it, I get a message telling me my version is out of date.
As indicated by ivor4781.....It is most important to accept Firefox up-dates to ensure that you maintain security levels. Similar to Ivor, I have my Browser set to automatically up-date and I suggest you do likewise, as follows :-
Click open Firefox and then the 'hamburger' (3 lines, top right of page) and proceed as follows :- Options > Advanced > Update >Automatically install updates. Also ensure there is a tick in the box (Warn me if this will disable any of my add-ons.)