Please refer to this bug I initially reported here for details: https://bugzilla.gnome.org/show_bug.cgi?id=731438 It looks like that any browser (including Gnome Web - Epiphany - 3.12 or a cutom gtk3 application embedding wekit2-gtk3 browser control) can't open http://www.youtube.com/ In any cases it displays a blabk page. Please see: https://bugzilla.gnome.org/show_bug.cgi?id=731438#c3 This is using webkit-gtk3 and it opens youtube site with no issues Then try compiling against webkit2-gtk3 like stated here: https://bugzilla.gnome.org/show_bug.cgi?id=731438#c4 This is showing a blank page exactly as with Epiphany. So this suggests that the issue is with webkit2-gtk3 2.4.3 package. As additional info, I'm on ArchLinux 64Bit.
Additional info: this is my user agent string with Epiphany. Mozilla/5.0 (Macintosh; Intel Mac OS X) AppleWebKit/538.15 (KHTML, like Gecko) Safari/538.15 Version/6.0 Epiphany/3.12.1