I recently enabled Archiving & Discovery for our userbase and subsequently installed the cross-mailbox search zimlet.
Whenever I click "Search Mail" in the Zimbra administrator interface I get:
Server Error Encountered
Message: unknown document: GetXMbxSearchesListRequest
Error code: service.UNKNOWN_DOCUMENT
I've recreated this using ?debug=3 appended to the URL but it doesn't provide any information. I also added the zmmboxsearch command to the sudoers file, since I've seen similar errors from commands not existing there.