What is BetterJsPop error on chrome?

I figured out that it was "Fair Ad Block" chrome extension issue. I disabled and reenabled extensions and found the ad blocker was causing the issue. I removed the extension and my code is running very well again.

It's part of the "Better Js Popunder Script", a JavaScript library to show popup/popunder windows with advertisements (and break your navigation at the same time). I may well be included in some Chrome extensions.

http://code.ptcong.com/better-js-popunder-script/