adsense script error ?

Why my approved Ads serving stoped without a warning but my account still approved but ads serving stopped?
yesterday it stop for some time and again visible after some time…… today from morning ads not serving .. after view source code from browser it is showing error —

http://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js.pagespeed.jm._14lL_qDXb.js
Failed to load resource: the server responded with a status of 404 (Not Found)

please help me for .. whats the resion?

My website is – http://freecareernews.com/

I also clear some points –
I didn’t got any mail from adsense.
Status is active .
No rules violation