ISSUE: Create O365 User step fails with error 'Invalid value specified for property 'mailNickname' of resource 'User'

Overview

The Create O365 User step fails with the error below. 

Request_BadRequest: Invalid value specified for property 'mailNickname' of resource 'User'. [ProcessResult]

Cause

The leaver name, in this case, was formatted as such causing the issue: LEAVER_user1_TerminationDate:6_30_2015.jones@xyz.onmicrosoft.com

Solution

1. Unmap the user

2. Find the user under the Leavers Mapping page

3. Modify the 'Constructed UPN' field with a new name such as:  LEAVER_User1_Jones@xyz.onmicrosoft.com

4. Map the user