I want to use a YouTube video that found, but when I embed the code, the page will not open....aero just keeps spinning. It is a long video, about 48 minutes. Would the length have anything to do with this problem?

I have entered:

<center><iframe width="420" height="315" src="//www.youtube.com/embed/UD4C2qBcotw" frameborder="0" allowfullscreen></iframe></center>