There should have been a list of 'what's new' included with this update, and a method to reset the features you modified. My windows 10 machine does not have a mouse wheel nor effective touch pad. The elevator scroll bar is my best way to see web content. Please Email me with the setting tweak to get it back. Searching within Firefox settings or within Mozilla help does not even find the issue... BAD FORM Mozilla, you look like Microsoft, breaking things for no good reason.