error on product page with marketpress

I am setting up a site/store for a client.
I cloned my working site to her site and am now getting an error message on the "product" page here:

While setting up my store, I also had the error but somehow fixed it.

I can't find what it causing the error on her site though. I have reinstalled the marketpress plugin to her site, but with no change.

The theme is flexmarket. Their support forum said to ask you for help.

I do have a paid account for marketpress.