cannot assign categories to new marketpress product

I’m using MarketPress to sell house plans. I use User Role Manager to create a custom role “Architect”. I understand that I have to enable certain capabilities to allow Architects to create/manage products. Everything seems to work fine except that they can’t assign a category to the products they create.

Here’s a screenshot of the “Architects” role capabilities:
https://fevaag.no/role.jpg

Here’s a screenshot of the product entry page. Notice that the list of categories is there but neither can be selected.
https://fevaag.no/product-entry.jpg

I understand that to allow them to manage products, I had to enable “edit_pages”, “delete pages”, “edit_published_pages”, etc.

My question is: What capability do I have to check to allow architects to assign categories to a product?

bump

If ‘Products’ custom post type doesn’t defines its own capabilities set for it, I suppose that you need include ‘edit_posts’ capability to the “Architect” role. Try, if that will help.

Why would you want a seller to create a category? Categories should be created and managed by the super admin.