Overview:

While migrating content from Vault, the following error message appears: Error: While upserting record [Record ID::Status] Cause: duplicate value found: Vault_External_Id_vod__c duplicates value on record with id [Record ID] even though there are no duplicate IDs in the system.

Root Cause:

This is caused by having Vault_External_Id_vod__c marked as External ID and Unique Case Sensitive when syncing over both Approved and Staged Content.  When both are being synced, this should never be the case.

Solution: