We all know just how difficult it is when it comes to testing seemingly countless configurations of servers with patches, and other components which are installed. Testing of a new release, like Enterprise Vault 11 is no different really. Sometimes though there is an oddity which is thrown up which defies rhyme and reason.
Take a look at this technote, titled: Enterprise Vault search: the preview pane contains "No preview of this item is available (Error Code: 0x8007007F)'
In this technote Symantec point out an issue with the combination of Enterprise Vault 11, and the SQL Reporting Services being installed on the same server, where the Enterprise Vault Reporting Configuration has never been run. I can tell you from experience that when you read it you think "Surely that should have been tested", but in reality these sort of things are amazingly difficult to test for. You'd end up with hundreds of test environments, which is just not practical.
Have you encountered the error described in the technote?