ESXi host fails to enter maintenance mode hanging at 2 percent with error : "Failed to enter namespaces maintenance mode due to Error"

Products

• VMware vCenter Server 8.0

Issue/Introduction

• ESXi host stalls at 2% while attempting to enter maintenance mode  with the below error : 
  Failed to enter namespaces maintenance mode due to Error: system_error Messages: vapi.send.failed<Send of frame failed: N7Vmacore15SystemExceptionE(Connection refused: The remote service is not running, OR is overloaded, OR a firewall is rejecting connections.)

• Verified the status of the WCP service using the command service-control --status wcp; the service was found to be in a STOPPED state.

Environment

vCenter Server 7.0.x

vCenter Server 8.0.x

Cause

The vCenter Workload Control Plane (wcp) service is stopped, breaking the vAPI communication endpoint required for the host to successfully process Supervisor cluster evacuation checks during the maintenance mode request.

Resolution

To Resolve this issue:

• Log in to the vCenter Server Appliance via SSH.

• Start the Workload Control Plane service by executing the following command: service-control --start wcp

• Verify the service has successfully started.

• Re-initiate the enter maintenance mode task on the affected ESXi host from the vSphere Client.