After changing the Retention Category in the Site Properties and the Provisioning Group to a new retention category, The ArchiveTask treats all
previously archived items as Moved items and attempts to update the Retention Category to the new Retention Category.
This occurs only if the Site Setting “Only when the retention period is increased” is used.
SolutionThis issue has been addressed in the following release:
Enterprise Vault 11.0.1 Cumulative Hotfix 3 Release
Enterprise Vault 12
The following link contains information about Enterprise Vault 12