Since my last Firefox upgrade (Mac 19.0.2), many websites that I rely on, that worked perfectly well in prior versions no longer work, either partially or fully (examples: Pandora, Apple Support, My Banking Site, Firefox Support--can't use the reply button, etc.). In some cases, the site won't load at all, but in many cases, simple functions like buttons just don't work. Whenever this happens I switch to Safari and everything works perfectly well. I have tried all the solutions offered in other parts of this support site (clearing cache, cookies, resetting, checking proxy settings, etc.), but none of this makes any difference. I like Firefox, but I'm so frustrated, I'm ready to give up on it.