vCenter Upgrade fails with "Error from Previous Upgrade attempt: The validation of the upgrade failed"

Products

• VMware vCenter Server

Issue/Introduction

This article provides information on how to troubleshoot and resolve this issue during vCenter upgrade

Symptoms:
Upgrading vCenter fails with  "Error from Previous Upgrade attempt: The validation of the upgrade failed".

Environment

VMware vCenter Server 8.0.x

Cause

This is due to the upgrade ISO being attached to the vCenter instead of the patch ISO.

Resolution

To perform the vCenter update by downloading the patch please follow the below procedure:
1. Go to the site:  https://my.vmware.com/group/vmware/patch
2. Product: VC; Version: e.g. 8.0 
3. Download the FP ISO. Upload the ISO to a datastore from which we would have to attach the ISO to the vCenter VM
4. Attach the ISO from the datastore from Edit Setting > Select Datastore pm CD/DVD > Attach the ISO > Check the option for connected
5. Login to VAMI->updates->check updates->check CD-Rom->Stage->Install

Additional Information

Impact/Risks:
Unable to proceed with the vCenter upgrade.