Vimb html5 videos

Hi,
I’ve came into a problem that I cannot overcome myself.

I’ve installed vimb package and tried to open some videos on youtube, but it says that the html5 video is not supported by this browser.

I’ve installed all the gst_all_1 packages as well as gstreamer and tried also vimb-unwrapped package against them…

Does someone know how to solve that issue?