ISSUE: Disable Archive step fails with error 'Object reference not set to an instance of an object'

Overview

During the Disable Archive step, it will fail with the error below:

'Object reference not set to an instance of an object. [Start] (1x)

Cause

This will occur when the user has been mapped under the 'Onboarding Mappings' section which should only be used when migrating a mailbox, not Enterprise Vault data.  

Solution

Unmap the user and re-map the user under the Mail Archive Mappings section