If someone adds a new listing in the Matrix asset and neglects to fill out anything, the listing ends up as on the list to be approved. Unfortunately, since there is no name for this listing, it can not be clicked and therefor not be approved or rejected.
Steps to reproduce:
Fixed in 7.3.20.
All Matrix Listing product names will have a default of "Undefined". The upgrade script will automatically rename blank product names to Undefined to fix existing Matrix Listings.