Concord drops targeting values that are not available in every country you are targeting, and names what it dropped. Snapchat availability is per country — a value valid in France can be rejected in Belgium.
Nielsen segments are gated by account entitlement, and this is not caught by the pre-flight check. If your account is not licensed for Nielsen, use the Snap-native equivalent category.
An ad squad reads back with no targeting, and edits fail
The squad has more than 500 targeting criteria. Above that limit, Snapchat moves the targeting into a sub-resource Concord does not manage. Split the criteria across several ad squads.A squad already in that state cannot be patched — recreate it, or fix it in Snap Ads Manager.
Snapchat re-validates the whole entity on every update. Objective and creative type are fixed once set. Create a replacement rather than trying to patch it.
The lens media itself is authored in Lens Studio or Web Builder and has to be added to the ad account in Snap Ads Manager first. Once it is there, re-run discovery so it synchronizes, then Concord can reference it.
Story Ads need a composite creative, which Concord cannot author. Build the creative in Snap Ads Manager — Concord can attach it to an ad once it is synchronized.