Even if you are avoiding the new Firefox 57, beware of updating the new Adblock Plus browser add-on to 3.0. According to the developer, the vital Element Hiding Helper for Adblock Plus 1.4 is…

“discontinued due to the new Firefox extensions system.”

You can get back to 2.9.1 (June 2017) on Firefox 55 or 56 here, which has a 2.9.1 version that still works with the latest Element Hiding Helper.

Update: I gave up on Firefox and moved to Opera.