Creating a Plan for VMware provider and add Pre and Post Play Ansible book to the new wizard and after creation of the plan, it end up with corrupted characters as you can see in the screenshots below

CNV: 4.18.6
OCP: 4.18
MTV: 2.9.0 - forklift-fbc-prod-v418:on-pr-e97186b9254c1432ca274681037b3643312888df

Always 

1. Create a VMware provider 
2. Create a cold migration plan to that provider and add Pre or Post
3. Finish creating the Plan
4. check the Pre or Post in the Plan

gibberish pre-hook / post-hook 

The Actual Ansible playbook