This advertisement uses a retired placement and cannot be edited
Admin ads API returned This advertisement uses a retired placement and cannot be edited. (thisAdvertisementUsesARetiredPlacement).
Why this happens
The ad’s placement slug is no longer supported (e.g. home-page ads retired). Updates are blocked; delete is the usual path.
Diagnose and fix
1. Delete the retired-placement advertisement.
2. Create a new ad on a current placement (Advertisements (ad slots)).
3. See Could not update advertisement for other save failures.
4. See Could not load advertisement if the editor will not open.