When "Revising your listing (with restrictions)"it says"Looks like something is missing or invalid. Please fix any issues and try again."Item specifics "Additional details are required: MPN"however you cannot edit the MPN when "Revising your listing (with restrictions)"Also cannot adjust quantity on-hand in this situation. The chat agent leads nowhere when trying to report this issue, so I'll do it here

MPN required when "Revising your listing (with restrictions)" | Ask a Mentor

MPN required when "Revising your listing (with restrictions)" | Ask a Mentor | eBay Community