During a run of the Exchange Mailbox Archiving task(s) numerous 6578 errors and 2270 warnings are generated in the Enterprise Vault event logs for folders which are configured as Exchange Managed folders.  This issue occurs during Moved Item updates of items contained in the Managed Folders, because archiving of these folders is disabled no retention is sent with the Move Item update request, which is evidenced by the following line in the 2270 Event:

FolderRetCat = "",

A DTrace of the ArchiveTask and StorageOnlineOpns processes during Shortcut Processing will show similar lines to the following:

161164 11:32:53.576  [1828] (ArchiveTask) <16216> EV:M CArchivingAgent::SendABatchOfMovedItemsForProcessing - found 8 moved items in folder \Managed Folder

277029 11:33:28.659  [1828] (ArchiveTask) <980> EV:L :AgentMessageDispenser::ActivateObject() |Called server side object, with arguments: |m_pIBackgroundArchivingAgent->ProcessMovedItemsInFolder2(ExchangeMailboxDn = "/o=ORGANIZATION/ou=First Administrative Group/cn=Recipients/cn=username",|  ArchiveID = "1D88C53466GC179857A6A7976431249C237437698EVSERVER",|  ArchiveFolderID = "2A62478998BC64A43D6574F897948D9741234587EVSERVER", |  FolderRetCat = "", |  SourceFolderID = "ID", |  FolderPathName = "�Managed Folder", |  CompressedItemRequestXML = "some XML", |  EVPMFolder = "TRUE") |

277049 11:33:28.659  [1828] (ArchiveTask) <980> EV:M CArchivingAgent::ProcessMovedItemsInFolder - processing moved items in folder '\Managed Folder' for user '/o=ORGANIZATION/ou=First Administrative Group/cn=Recipients/cn=username'

277113 11:33:28.675  [1828] (ArchiveTask) <980> EV:M CArchivingAgent::ProcessMovedItemsInFolder - 8 moved items to send to storage for update of location and retention - <EVUpdatableMetadata Version="1"><Update><Property Id="1" Value=""/><ItemsContainer Id="1D88C53466GC179857A6A7976431249C237437698EVSERVER"><Property Id="2" Value="2A62478998BC64A43D6574F897948D9741234587EVSERVER"/><Items><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/><Item SSID="201101010101000~201103010101000000~Z~123A45BCD6EF789ABCD01EFA1BC23DE4"/></Items></ItemsContainer></Update></EVUpdatableMetadata>|

277123 11:33:28.706  [4188] (StorageOnlineOpns) <4256> EV~E Event ID: 6578 Abnormal error occurred | |Object:    CRetentionCategoryCache |Reference: LE/RE |
277124 11:33:28.706  [4188] (StorageOnlineOpns) <4256> EV~E Event ID: 6578 Abnormal error occurred | |Object:    CRetentionCategoryCache |Reference: RE(1)/fe |

For more information on Dtrace please refer to the link the Related Articles section. 

If archiving of the Exchange Managed Folders is desired then changing the Exchange Mailbox Policy > Advanced tab setting for Archive Exchange Managed Folders to either Normal or Managed will resolve these errors and warnings.

However if archiving of the Exchange managed Folders is not desired then there are several possible workarounds. 

NOTE:  It may be necessary to perform some of the procedures multiple times and whenever a new Mailbox is enabled for Archiving within the environment:

Workaround 1 changes the Archive Exchange Managed Folders and uses Enterprise Vault Policy Manager (EVPM) to disable archiving on the managed folders:

1. Change the Exchange Mailbox Policy > Advanced tab setting for Archive Exchange Managed Folders to Managed or Normal depending on the type of retention category that should be applied to this folder
2. Perform a Synchronization on each Exchange Archiving Task across all mailboxes
3. Run an EVPM script against the affected Mailboxes to disable archiving, a sample script can be found in the related Technote (TECH35607)

Workaround 2 disables updating of Moved items:

1. On the Exchange Mailbox Archiving policy's Moved Items tab disable Update archive location for items moved in the mailbox
2. Perform a Synchronization on each Exchange Archiving Task across all mailboxes

Workaround 3, this process would need to be performed at least after any of the errors had occurred:

1. Change the Exchange Mailbox Policy > Advanced tab setting for Archive Exchange Managed Folders to Managed or Normal depending on the type of retention category that should be applied to this folder
2. Perform a Synchronization on each Exchange Archiving Task across all mailboxes
3. Execute a Run now of the Exchange Archiving Task for only Shortcut Processing against all mailboxes, or those Mailboxes currently causing the errors
4. Once completed, evidenced by the A3 and A6 Microsoft Message Queues reducing down to '0' items, the policy Archive Exchange Managed Folders can be set back to Off
5. Perform a final Synchronization on each Exchange Archiving Task across all mailboxes

This issue has been addressed as part of the following release:

Enterprise Vault 10.0 - Release Details

*This issue has been also identified when using EVPM generated Retention Folders where one Retention Folder is moved to a different Retention Folder.

Example:
Original configuration -

Inbox
  Retention Folder 1
  Retention Folder 2

After moving the Retention Folder -

Inbox
  Retention Folder 1\Retention Folder 2

In this scenario, a Dtrace of StorageOnlineOpns, as referenced above, is needed to identify the affected user, then the following is performed:

a. Run EVPM to 'zap' the mailbox, to remove the current hidden message and filter messages.
b. Move the folder and contained items back to their original location.
c. Enable the affected user for archival.
d. Run the original EVPM script against the user to reassign the Retention filter messages.