If you are wondering why Videos can't be Loaded on websites, then this Extension is very FAULTY.
I had to Uninstall this Extension, Because it was Blocking a Live TV channel website, from my Country Cyprus:
http://www.sigmatv.com/live
It couldn't load the video to watch the channel. Other browsers was loading the video with no problem.
I discovered that it was this Addon, Because I had to go through a "Painstaking process" Disabling ALL of my addons and start Enabling them back again from the start. One-by-one, to discover which Addon was faulty.
And this addon was blocking this channel video.