Invalid configuration structure, validation failure, invalid destination target, or blocked destination deletion. Destination target errors (type bloomreach/datahub/item-collections/destinations/target-invalid) are returned when engagement project IDs or discovery account/catalog/environment combinations cannot be resolved for the current workspace. These are distinct from payload shape errors (type bloomreach/datahub/api/request-body-invalid), which indicate structurally invalid request data. Removing destinations without force_delete=destinations may be rejected. Even with force_delete=destinations, deletion may still be blocked if associated downstream destination resources, such as Engagement catalogs, are still used by other systems.