I have the latest Firefox and Flash Player installed. But some applications just don't run at all. For example, videos on https://www.guildwars2.com/en/media/videos/
just show a black screen. And this site is remains completely blank: thisissand.com
. These applications do work fine on Internet Explorer, but no matter what I try, it won't work on Firefox. Some other things, like Flash movies on http://newgrounds.com
work just fine on Firefox.
I've already tried re-installing Flash. Tried an older version of Flash. Tried disabling Flash safe mode. Nothing changes.
Looking for help.