Not only I tried a fresh reinstall, I tried resetting all settings, safe-mode, rebooting, disabling hardware acceleration, upping the amount of processes FF uses, ALL the solutions the questions normally had... you name it. This won't be solved by any of the other solutions I found here or anywhere else. EVERY SINGLE TIME I open a new tab, FF Quantum (version 57, up to date as of today November 16th) freezes for 5 to 15 seconds. If I have a youtube video opened for example, the sound keeps playing (so the video is still playing on the "background") but I can't click anywhere or do anything, can't close the browser either if I don't open the task manager and shut down the process. It's getting REALLY annoying, but I want to get a fix before I definitely decide to swap to Chrome. Please, don't make me switch to Chrome.