GTIN Exemption - Fix 1 errors before submitting your listing

Hi

I am trying to set up a product to sell some coffee cups i have had manufactured. I put in a request for a GTIN exemption which was approved straight away (under home and garden).

When I open up the add a new product page, the product ID is no longer highlighted. However, as i move through the steps, it then turns red and I get the error message Fix 1 errors before submitting your listing.

I’m not quite sure how to progress?

Thank you