Pop Pro not firing on website.

I have popup pro set to fire on almost every page on the site. Here is one that should work (http://www.statisticssolutions.com/factor-analysis-sem-exploratory-factor-analysis/). I have flushed cookies and used an incognito window and multiple computers and it will not work. I think there may be a java script conflict but I can't figure out it out. I have been using the plugin successfully for a long time. Please help me figure out why it is not firing. I'm missing out on a lot of leads.

Thanks,
jimmy