Portfolio page listing two categories of products as sold in error

I have split two portfolio categories in two by listing under the "projects" category however when I've gone back to edit, squarespace seems to think that i have sold all products (sadly not true) and when I've gone in to see why, it has thrown an error. 

Screenshots attached, currently using squarespace v7.1, unable to find name of template (will not display underneath version). 

This is so frustrating, I'm meant to launch today as I'm applying for grants and exhibitions tomorrow and my site needs to be functional, not showing in error.