That “delivery error” strikes more often than you’d think—even on spotless accounts—because it’s really Facebook’s catch-all for anything that’s blocking an ad from ever entering the auction. In my experience it usually boils down to one of two things: either the payment method or spending limit on your Business Manager isn’t quite cleared for that new campaign, or your targeting and budget settings are so narrow (or your bid so low) that Facebook can’t find eligible impressions.
I ran into this last month when I spun up a clean ad account to test a new creative, and despite having a fresh card on file, the campaign sat in “Not Approved (Delivery Error)” until I bumped up the daily budget and expanded my audience by a few hundred thousand people. Once I did, it leapt straight into review and then into delivery.
What you can do right now is double-check your billing threshold in Business Settings, make sure your daily or lifetime budget meets the minimum for your objective, and open up your audience or bid so Facebook has room to work. If all of that looks solid and you still see “delivery error,” hit up the “Chat with Support” link in Ads Manager, ask them to inspect the ad set’s delivery diagnostics, and they can often spot a hidden block (like a suppressed placement or a flagged payment method). Once you clear that hurdle, your campaign should finally go live.