Configuration Manager manifest synchronization failing since 8 July 2026

Hi rajha1750, because this started at the same time across three independent hierarchies, I would suspect a Microsoft service-side issue or endpoint response change rather than a local hierarchy problem. Keep the small two-byte response file, SMS_DMP_DOWNLOADER logs, timestamp, tenant ID, ConfigMgr version, and the exact endpoint response. I would open a Microsoft support case and mention that multiple unrelated environments are receiving only OK instead of a valid manifest CAB.