The system returns a 400 Bad Request error. NSX Manager certificate replacement operations fail when attempting to replace existing certificates.

Products

• VMware NSX

Issue/Introduction

Issue Clarification

The failure occurs in environments where the certificate was originally created by the nsx_policy service. This affects VMware NSX-T 4.1.2.5 and potentially other versions where policy-based object ownership is enforced.

The error code MP289 is returned during the API request. The specific error message states: Principal 'admin' with role '[enterprise_admin]' attempts to delete or modify an object of type nsx$Certificate it doesn't own. (createUser=nsx_policy, allowOverwrite=null).

Verify this by checking 

/var/log/proton/nsxapi.log 

on the NSX Manager nodes.

Attempting to use the standard UI or CLI certificate replacement fails with this ownership violation.

Environment

VMware NSX

Cause

The root cause is an object ownership conflict. The certificate object is owned by the nsx_policy user system. The current user session, even with enterprise_admin privileges, is identified as admin. The NSX ownership model strictly prevents an object creator mismatch to ensure configuration integrity, blocking the modification of certificates managed by policy.

The failure is confirmed by the presence of the createUser=nsx_policy string within the 400 Bad Request API response body. Attempts to bypass this using standard administrative credentials fail because the system defaults the allowOverwrite parameter to null, which does not grant the required override permissions for policy-owned objects.

Resolution

 To replace the certificate, the API request must explicitly override the ownership check using the X-Allow-Overwrite header.

1. Identify the Certificate ID and Node ID using the appropriate GET request.
2. Prepare the new certificate import.
3. Execute the POST request to apply the certificate with the override header: curl -k -u admin -X POST "https://<NSX-IP>/policy/api/v1/infra/certificates/<CERT-ID>?action=apply_certificate&node_id=<NODE-ID>&service_type=API" -H "X-Allow-Overwrite: true"
4. Verify the application status in the NSX Manager UI.

The X-Allow-Overwrite: true header is a documented API mechanism for administrative overrides in NSX. By setting this header, the ownership guard is suppressed for the specific request, allowing the administrative user to update the certificate object despite the mismatch in the original createUser attribute. This successfully remediates the MP289 error without impacting NSX Manager stability.