If the ICON Note was not present in the mail file, then archive processing would fail to continue with error 'Special database object cannot be located'.
Event ID 41162 Error: Special database object cannot be located during Domino Mailbox Archiving.
This issue has been resolved in a Cumulative Hotfix for Enterprise Vault for Lotus Domino 9.0 SP2.
This issue has also been resolved in the following releases:
Enterprise Vault 9.0.3 - Release Details
Enterprise Vault 10.0.1 - Release Details