When using an Enterprise Vault Journal Archive collection as part or all of a Collection Set, the job will fail immediately.
[#460203] An unexpected error occurred: unexpected type: 29 can't cast to type: 16
The problem occurs when a Custodian Filter is applied.
Copy the PST collection to a new folder structure and treat the data as a Case Folder source OR remove the Custodian filter on the Collection Task.
This issue is resolved in Clearwell eDiscovery Platform 7.1.2 Fix 1 or higher.