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 ;-)

The Flashbulb - Black Lawn Finale

Benny L & PAV4N - Grim

Mat Zo ft. Olan - Reflections

Netsky & Rudimental & Afronaut Zu - Blend

London Elektricity - Final View From The Rooftops ft. Cydnei B (Justin Hawkes Remix)