Each update operation successfully performs the update for one certificate and key, or fails in a way that preserves the original state. If an update fails, you might need to roll back the failed step.
Before beginning the update process, the vCenter Certificate Automation Tool saves a copy of the existing certificate information in a backup folder, ensuring that you can roll back to the previously used certificate to keep the entire system up and running.
You can use the tool's menu item to let you roll back to the original.
After rolling back the vCenter Server certificate, you must update the vCenter Server trust to VMware Update Manager again.