Error 8058 - flat file upload/Parent SKU

So, I’ve been running around in circles with Amazon help, with every call I receive getting cut off or email response being the same regurgitated guidance. It’s been weeks, and I’m still no closer to fixing this. Please, anyone, help! The only advice I’ve had that’s been useful is from the forums, so thank you.

I’m having trouble with creating Parent SKUs via a flat file upload. The advice I receive is below, but I cannot get clarity on what the ‘missing attributes’ are in my report. Nothing is highlighted and ‘Required Fields’ aren’t all required for a Parent SKU.

The exact error I get is: “Some attributes are missing for SKU: [ZSS2020001].For more details, see http://sellercentral.amazon.co.uk/gp/errorcode/8058”

Error code 8058 – The minimum requirements have not been met. Required fields are missing data.

This error occurs when you did not provide a value for the specified field name for your product.

Your processing report will show you the SKU number of the product and the field name that was not filled in.

There are certain fields of templates that are required in order for the system to process the feed.