Marketpress invalid argument error

Just updated Marketpress. I had recently installed the last version, it seemed to be working with no errors. Now I'm getting an error above my products. I'm running the latest wordpress and a single site. Nothing fancy. Using Authorize.net as the gateway.

This is the error: Warning: Invalid argument supplied for foreach() in /home/smsite/public_html/blog/wp-content/plugins/marketpress/marketpress.php on line 2034

This error doesn't show up on computers that are not logged in. Is this something I need to fix? I'm not a programmer, but I'm not new to going in and changing code. All help appreciated.