After Installing Exchange 2010 Service Pack 1, Searching via OWA or Outlook Online Mode Fails

With Exchange 2010 Service Pack 1, you may find that performing a search via Outlook Web App (OWA) results in an error message, “The action couldn’t be completed. Try again later.” Additionally, Outlook clients operating in Online Mode can no longer search for attachments or embedded emails.

What causes this issue?

This problem typically is a result of installing or upgrading a multi-role server (a server that has the Mailbox, Client Access, and Hub Transport roles installed) to SP1 and then removing the Hub Transport and Client Access roles, thereby leaving the server with only the Mailbox role installed.

There is a symbolic link for each language referenced in the registry, HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ContentIndex\Language. The symbolic links (ActiveX CLSID of the class used) allow for word breaking and stemming for the locale corresponding to the language.

During the Exchange 2010 Service Pack 1 uninstall process for the Hub Transport role, setup removes the symbolic links, regardless of the fact that the Mailbox role is still present. The removal of the symbolic links causes the generation of content indexing files to fail.

How do we resolve this issue?

You will need to execute a script on the affected Mailbox servers that reinstalls the symbolic links:

1. Download the script Repair-ExchangeSearchSymlinks.ps1 from the Script Center.
2. Copy the Repair-ExchangeSearchSymlinks.ps1 script to the Scripts directory (default installation is C:\Program Files\Microsoft\Exchange Server\v14\Scripts).
3. Open the Exchange Management Shell.
4. Within the Exchange Management Shell, navigate to the Exchange Scripts directory.
5. Within the Exchange Management Shell, run the following script:

   .\Repair-ExchangeSearchSymlinks.ps1

6. Within the Exchange Management Shell, run the following script (without the symbols [] and substitute the database name(s) for any databases you wish to reset:

   .\ResetSearchIndex.ps1 [-force] <dbname> [<dbname>]...

7. You will receive an Event ID 109 when the rebuilding of the index starts for each database and an Event ID 110 for each database when the index rebuild has completed.
8. After receiving Event ID 110 for each database, test to make sure search functions correctly with both OWA and Outlook operating in Online Mode.

more at the sorce: http://blogs.technet.com/b/exchange/archive/2011/06/30/after-installing-exchange-2010-service-pack-1-searching-via-owa-or-outlook-online-mode-fails.aspx