I have been getting the following error in the event viewer.
At '8/12/2014 10:35:54 AM' the Microsoft Exchange Information Store Database 'Database' copy on this server experienced a corrupted search catalog. Consult the event log on the server for other "ExchangeStoreDb" and "MSExchange Search Indexer" events for more specific information about the failure. Reseeding the catalog is recommended via the 'Update-MailboxDatabaseCop
I have ran this command from EMS...
Then I got the attached error when trying to run the cmd.