I haven't had a single issue with Firefox (54) out of the box. I know that some add-ons can break the multi-process windows feature, but out of the box has been

I haven't had a single issue with Firefox (54) out of the box. I know that some add-ons can break the multi-process windows feature, but out of the box has been fine, both with clean VirtualBox installs and bare-metal desktop installs.