Could not update advertisement
Admin ads API returned Could not update advertisement. (couldNotUpdateAdvertisement) when saving changes fails.
Why this happens
Validation, retired placement (Phase 71), slot conflict, CSRF, or server error. Distinct from Could not create advertisement / load failures.
Diagnose and fix
1. Refresh; reopen the ad; retry save.
2. Check placement is still valid and not conflicting.
3. See Could not load advertisement if the editor will not open.
4. See Advertisements (ad slots).