If Youtube videos do not play reload the page, that's a Youtube bug.
Or maybe now, a few years later, it's a new bug ;-)

Showtek Feat. We Are Loud! and Sonny Wilson - Booyah

Major Lazer - Watch Out For This (Juicy M & Emzy Remix)

Showtek and Noisecontrollers - Get Loose (Tiësto Remix)

A-Trak & Tommy Trash - Tuna Melt

Flarup - Hardstyle Ambassadors