SDDC Manager Validate Draft Fails with Failed to Serialize/Deserialize Object

Products

• VMware vCenter Server

Issue/Introduction

When attempting to validate a draft configuration for a cluster during SDDC upgrade in VMware Cloud Foundation (VCF) SDDC Manager, the task fails during the vSphere Lifecycle Manager (vLCM) validation phase.

The SDDC Manager UI displays the following error: Validate draft task failed for cluster <REDACTED_HOSTNAME> with error(s): Failed to Serialize/Deserialize Object.

The SDDC Manager Domain Manager log (/var/log/vmware/vcf/domainmanager/domainmanager.log) contains the following exception:

ERROR [vcf_dm,] [c.v.e.s.o.model.error.ErrorFactory,]
FAILED Validate draft task failed for cluster <REDACTED_HOSTNAME> with error(s): Failed to Serialize/Deserialize Object.
com.vmware.evo.sddc.orchestrator.exceptions.OrchTaskException: Validate draft task failed for cluster <REDACTED_HOSTNAME> with error(s): Failed to Serialize/Deserialize Object.
at com.vmware.vcf.common.fsm.plugins.action.impl.ValidateDraftOnClusterAction.execute

The vSphere Lifecycle Manager log (vmware-vum-server.log) captures the ValidateDraftTask failure and the serialization fault:

info vmware-vum-server[] [Originator@sub=PM.AsyncTask.ValidateDraftTask{9}] [vciTaskBase ] SerializeToVimFault fault:
--> (vmodl.fault.SystemError) {
-->    reason = "vLCM Task failed, see Error Stack for details."
-->    msg = "{
-->      "error_type": "ERROR",
-->      "messages": [
-->          {
-->              "default_message": "Failed to Serialize/Deserialize Object.",
-->              "id": "com.vmware.vcIntegrity.lifecycle.drafts.VmaCoreError"
-->          }
-->      ]
--> }"

Reviewing the managing vCenter Server's vpxd.log (/var/log/vmware/vpxd/vpxd.log) reveals concurrent failures attempting to extract the image profile from an ESXi host, throwing 503 Service Unavailable and HostCommunication faults:

SOAP request returned HTTP failure; <<io_obj p:0x..., h:82, <UNIX ''>, <UNIX '/var/run/envoy-hgw/hgw-pipe'>>, /hgw/<REDACTED_HOSTNAME>/vpxa>, method: queryHostImageProfile; code: 503(Service Unavailable); fault: (null)
Cannot contact the specified host (<REDACTED_HOSTNAME>)
N5Vmomi5Fault17HostCommunication9ExceptionE(Fault cause: vmodl.fault.HostCommunication

Environment

VMware Cloud Foundation 5.2x
VMware vCenter Server 8x
VMware vSphere ESXi 8x

Cause

This issue occurs because the cluster image source file, which was edited and staged by the hardware vendor (e.g., Lenovo), contains malformed data or formatting errors. This prevents the backend vCenter and vSphere Lifecycle Manager (vLCM) services from successfully parsing and deserializing the JSON configuration payload, causing the draft validation task to fail.

Resolution

1. Contact your hardware vendor to review and correct any syntax, schema, or formatting errors in the custom cluster image source file.

2. Once the image source file has been corrected by the vendor, stage the new file in SDDC Manager.

3. Retry the "Validate Draft" task for the cluster in the SDDC Manager UI.