You may see this error below on one of your eBay listings. This is letting you know that a required field has been left blank. The instructions below will show you how to resolve this issue.
First, you will need to select the gear icon associated with the "incomplete" status
From here, you will be taken to the listings edit page for the eBay listing. There are 3 tabs at the top of the page, you will need to select the "Category" tab and fill in the highlighted field below "Brand".
Once you have filled out the Brand, save changes. This will trigger a sync from Listing Mirror --> eBay. Voila! You're incomplete issue has now been resolved!