Getting an error in my error log every 10-15 seconds from pop-up pro

Hello WPMUers!

I'm noticing in my error log that this plugin has the same error every 10-15 seconds. Is it normal?

Here is what it says:

[26-Aug-2015 00:57:34 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/suiteone/public_html/wp-content/plugins/popover/inc/class-popup-public.php on line 190

Your help is greatly appreciated,

Paul