Add the missing attribute to your product data
On this page
Why this issue is happening
One or more of your products is missing the country [country] sub-attribute of the shipping [shipping] attribute, which is required to use the shipping attribute.
How to fix your issue
To fix this issue, ensure that all required attributes and sub-attributes have been added for the affected products.
Fix products one by one directly in Merchant Center
Go to Products in Merchant Center, then select the Needs attention tab.
Use the filter icon 
above the table to find all products affected by your issue.
Click on the title of the product you want to fix, then click Edit product.
Add valid values for the required sub-attributes.
Click Save
Fix multiple products at once
Go to Products in Merchant Center, then select the Needs attention tab.
Use the filter icon above the table to find all products affected by your issue.
Select the download icon 
to download a list (.csv) of all affected products for all issues or this particular issue.
Cross reference the downloaded list with your uploaded product data and provide valid values for the required sub-attributes for all of your products.
Reupload your corrected product data to Merchant Center using your chosen upload method.
Next steps
After making the requested changes, check that you’ve fixed the issue by making sure it’s no longer listed on the “Needs attention” page.
Keep in mind: It may take some time for your change to be reflected on the “Needs attention” page.