A Zarafa user using Outlook 2010 complained that he suddenly was unable to reply to a message from a mailbox from another user he had access to. When he clicked ‘reply’ in Outlook the only vague message he gets was: The attempted operation failed. An object could not be found.
The message isn’t very informative; it doesn’t contain any clues. After some research it turned out that this was caused after installing Outlook update kb3114756. This update breaks some functionality of the Zarafa Outlook client. (More precise: the update changed functionality the Zarafa Outlook client can’t handle.) After uninstalling this update the user was able to reply to messages in other mailboxes again.
To ensure this update does not installs again the next update cycle, the update can be made hidden. A TechNet article describes in general how to hide an update. If you do this with the update mentioned before, you’ll be good for the next update cycles. Before you do this, make sure you read the article to decide if the fix doesn’t aply to you. If so, the user has to choose what functionality he prefers.