Default Baseline Scan or Remediation may fail using VUM with "An error occurred while communicating with the remote host"

Products

• VMware vCenter Server 8.0
• VMware vSphere ESXi 8.0

Issue/Introduction

• Scan or Remediation of Default Baselines which includes critical baseline, non-critical baseline and Security baseline using VUM is failing intermittently with the ERROR "An error occurred while communicating with the remote host" 
• /var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server.log

YYYY-MM-DDTHH:MM:SS error vmware-vum-server[48871] [Originator@6876 sub=SingleHostScanTask.SingleHostScanTask{29}] [singleHostScanTask 424] SingleHostScan caught exception: FaultMessage: Unknown MethodFault Error on Host: An error occurred while communicating with the remote host. with code: -1

YYYY-MM-DDTHH:MM:SS error vmware-vum-server[48871] [Originator@6876 sub=SingleHostScanTask.SingleHostScanTask{29}] [vciTaskBase 725] Task execution has failed: FaultMessage: Unknown MethodFault Error on Host: An error occurred while communicating with the remote host.
YYYY-MM-DDTHH:MM:SS verbose vmware-vum-server[48871] [Originator@6876 sub=SingleHostScanTask.SingleHostScanTask{29}] [vciTaskBase 889] New progress 100 for SingleHostScanTask{29}
YYYY-MM-DDTHH:MM:SS verbose vmware-vum-server[48871] [Originator@6876 sub=VciRemediateTask.RemediateTask{20}] [vciTaskBase 889] New progress 30 for RemediateTask{20}
YYYY-MM-DDTHH:MM:SS info vmware-vum-server[48871] [Originator@6876 sub=VciClusterPrePatchScanTask.VciClusterPrePatchScanTask{27}] [vciTaskBase 754] A subTask finished: SingleHostScanTask{29}
YYYY-MM-DDTHH:MM:SS error vmware-vum-server[48871] [Originator@6876 sub=VciClusterPrePatchScanTask.VciClusterPrePatchScanTask{27}] [vciClusterPrePatchScanTask 213] Patch scan task failed for host : host-xx. This host will not be remediated

Environment

vCenter 9.0.0 

VMware vSphere ESXi 8.0

Cause

vpxa crashed with out of memory issues when  the scan used the  deprecated method vim.host.PatchManager.ScanV2.

Resolution

This issue is resolved with vCenter Server 9.0

As a workaround, post vpxa is restarted re-attempt the failed task (scan or remediation).