While upgrading servers, the upgrade would fail. In the Symantec Management Agent (SMA) installation and agent logs, we see warnings after attempting to register the core agent service.
*WARN AeXUtility: CreateService('AeXNSClient'): Failed to create service because the service is marked for deletion, waiting for it to be released, remaining retries 1440
Third-party monitoring application interfered with the upgrade scripts.
Disabling the third-party application allowed the upgrade to successfully complete.