Invalid argument message-my theme?

Warning: Invalid argument supplied for foreach() in /home/content/09/9133209/html/wp-content/themes/angelo/includes/loop-portfolio2col.php on line 79

This appears when I click in my Store, under a particular Heading such as Interpretive.

I have no idea what this means but it’s really irritating.

Would someone please tell me what it means and how I can make it go away?

Thanks so much.