TL;DR: try recompiling everything. You can ask emacs to, or you can just force it to:
find ~/.emacs.d -name "*.elc" -delete
Then restart emacs.
The main culprits for this error are:
I recently had to uninstall/reinstall my brew casks and recipies because I had royally screwed something up. I have a script to re-install all the things I want so it was no drama except for the downloads and re-install, and some oversights when I uninstalled brew. So here is what I think I should have done:
$ for APP in $(brew cask list); do brew cask uninstall $APP done
|#### Sonic Pi -*- mode:ruby -*-|
|# Bach Preludes & Fugues 1-12 Well Tempered Clavier|
|# Book 1, Prelude 1. Transcribed from|
|define :bach do |n||
|#play an array of notes twice, with the last 3 repeated each time|
|#this is the pattern used repeatedly in Prelude no.1|
Open about:config and set
mousewheel.default.delta_multiplier_y to negative, e.g.
-100 if the current value is (the default)
This should only be necessary on platforms where Firefox isn't honouring the global setting. For instance on a Mac or Windows it's not necessary if you've set the scrolling direction to reverse globally, but on Linux, Firefox doesn't honour KDE's setting. I haven't tested GNOME ….
The default setting is fine for an actual mouse-wheel, but when using a touchpad to two-finger-scroll (or a trackball), it's more Natural for the page to scroll down when you swipe your fingers up: it seems more like how a paper page will shift.