Exchange 2010 SP2 upgrade fails (Mailbox Role) - defbrkr.dll

Hi All,

I had been trying to update all passive Exchange Mailbox servers 2010 SP1 to SP2 last week, but it wasn't successful.

The install fails during the installations for "Mailbox Role" and the error are as follows:

[03/14/2013 11:55:24.0245] [1] Executing: 
          install-ContentIndexingService
[03/14/2013 11:55:24.0245] [2] Active Directory session settings for 'Install-ContentIndexingService' are: View Entire Forest: 'True', Configuration Domain Controller: 'DC01.dc.com.sg', Preferred Global Catalog: 'DC01.dc.com.sg', Preferred Domain Controllers: '{ DC01.dc.com.sg }'
[03/14/2013 11:55:24.0245] [2] Beginning processing install-ContentIndexingService
[03/14/2013 11:55:24.0494] [2] Exception : srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
[03/14/2013 11:55:24.0510] [2] [WARNING] An unexpected error has occurred and a Watson dump is being generated: srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
[03/14/2013 11:55:24.0510] [2] [ERROR] srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
[03/14/2013 11:55:25.0555] [1] The following 1 error(s) occurred during task execution:
[03/14/2013 11:55:25.0555] [1] 0.  ErrorRecord: srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
[03/14/2013 11:55:25.0555] [1] 0.  ErrorRecord: System.Exception: srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
   at Microsoft.Exchange.Management.ContentIndexing.Tasks.ManageContentIndexingService.CreateOrDeleteSymbolicLinks(Boolean shouldCreate)
   at Microsoft.Exchange.Management.ContentIndexing.Tasks.InstallContentIndexingService.InternalProcessRecord()
   at Microsoft.Exchange.Configuration.Tasks.Task.ProcessRecord()
   at System.Management.Automation.CommandProcessor.ProcessRecord()
[03/14/2013 11:55:25.0571] [1] [ERROR] The following error was generated when "$error.Clear(); 
          install-ContentIndexingService" was run: "srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2".
[03/14/2013 11:55:25.0571] [1] [ERROR] srcFile: 'C:\Windows\System32\naturallanguage6.dll', lnkFile: 'C:\Program Files\Microsoft\Exchange Server\V14\Bin\defbrkr.dll', Error code: 2
[03/14/2013 11:55:25.0571] [1] [ERROR-REFERENCE] Id=ContentIndexComponent___<COMPONENET ID> Component=EXCHANGE14:\Current\Release\Shared\Datacenter\Setup
[03/14/2013 11:55:25.0571] [1] Setup is stopping now because of one or more critical errors.
[03/14/2013 11:55:25.0571] [1] Finished executing component tasks.
[03/14/2013 11:55:25.0602] [1] Ending processing Install-MailboxRole
[03/14/2013 11:57:56.0721] [0] End of Setup

I could not find any similar reported problems online as reference.

Any help will be appreciated. Thanks.