The behandelaar approval closes the zaak via OpenZaak. A related informatieobject with indicatieGebruiksrecht left null makes OpenZaak reject the close (400 indicatiegebruiksrecht-unset), surfacing as a 500 and failing the registration e2e flow. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>