Enabling HA on cluster failed after updating vCenter to 9.0.2

Products

• VMware vCenter Server

Issue/Introduction

• Cannot complete the configuration of vSphere HA agent on the host "Setting desired image spec for cluster failed"
• Set solution: General System error occurred: Image is not valid Soft Solution com.vmware.nsxt with version 9.0.2.0-25150387 cannot be found in depot. As seen in: /var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server-####.log

  YYYY-MM-MMTHH:MM:HH.SSSZ error vmware-vum-server[55553] [Originator@6876 sub=com.vmware.vcIntegrity.lifecycle.SetSolutionTask] [SetSolutionTask 412]  Set solution failed. entityId: domain-c#### Problems found while validating the new software spec: {
  -->     "errors": [
  -->         {
  -->             "id": "com.vmware.vcIntegrity.lifecycle.EsxImage.SolutionNotFound",
  -->             "message": {
  -->                 "args": [
  -->                     "com.vmware.nsxt",
  -->                     "9.0.2.0-25150387",
  -->                     "",
  -->                     ""
  -->                 ],
  -->                 "default_message": "Software Solution com.vmware.nsxt with version 9.0.2.0-25150387 cannot be found in depot.",
  -->                 "id": "com.vmware.vcIntegrity.lifecycle.EsxImage.SolutionNotFound",
  -->                 "localized": null,
  -->                 "params": null
  -->             },
  -->             "originator": null,
  -->             "resolution": null,
  -->             "retriable": null,
  -->             "time": "YYYY-MM-MMTHH:MM:HH.SSS",
  -->             "type": null
  -->         }
  -->     ],
  -->     "info": [],
  -->     "warnings": []
  --> }

• Cannot find vSphere HA master agent: "vCenter Server is unable to find a master vSphere HA agent in cluster"

Environment

• VMware vCenter Server 8.x 
• VMware vCenter Server 9.x
• VMware ESXi 8.x
• VMware ESX 9.x

Cause

This issue occurs when the vSphere Lifecycle Manager (vLCM) depot metadata is inconsistent or missing a specific solution version that the cluster's desired image is attempting to validate. This is common after a vCenter patch where the image validation process looks for components (like NSX-T agents) that are not currently synchronized in the local depot.

Resolution

Option 1: Cluster Image Revalidation

1. Navigate to the Cluster > Updates tab > Image section.
2. Click Edit.
3. Change the ESXi Version in the drop-down to the version matching your current hosts (e.g., 8.0.3).
4. Click Save to trigger a new compliance check.
5. Re-enable vSphere HA.

Option 2: API-Based Depot Cleanup

Open the vSphere UI, navigate to Developer Center -> API Explorer

1. Navigate to Developer Center > API Explorer.
2. Select ESX API and locate GET /api/esx/settings/depots/offline.
3. Execute the call and find the Identifier for the solution version (e.g., com.vmware.nsxt:9.0.2.0-####) mentioned in the logs.
4. Locate DELETE /api/esx/settings/depots/offline/{depot}?vmw-task=true and execute using the identified ID. 
5. Restart the Update Manager service:

   service-control --restart vmware-updatemgr

6. Re-enable vSphere HA once the sync completes.