"Error: Internal error occurs during VMware vSphere Update Manager pre-upgrade checks." while migrating Windows 5.5 VC to VCSA 6.5 fails during the pre-check

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

• Update Manager is not installed on vCenter 5.5
• No extension from vSphere client
• Trying to remove the Update Manager extension from vCenter Server MOB (Managed Object Browser) page fails.
• While migrating 5.5 vCenter to 6.5 vCenter Server Appliance precheck fails with Error: Internal error occurs during VMware vSphere Update Manager pre-upgrade checks.

Environment

VMware vCenter Server Appliance 6.7.x
VMware vCenter Server Appliance 6.0.x
VMware vCenter Server 5.5.x
VMware vCenter Server 6.0.x
VMware vCenter Server Appliance 6.5.x

Cause

Issue happens when Update Manager service is either not running or not installed.

Resolution

Check if update manager services is installed:

• If Update Manager is not installed, Install the update manager from the ISO image of current version of vCenter Server.
• Post installation re-run the Migration assistant.

Make sure Update Manager service started:

• If the Update Manager services is not running please start the services from services.msc on Windows Based vCenter Server. 
• Re-run the Migration assistant.