Installing Exchange 2013 CU1 on a production server fails: Couldn't mount the database that you specified.

Error:

The following error was generated when "$error.Clear();

          $name = [Microsoft.Exchange.Management.RecipientTasks.EnableMailbox]::DiscoveryMailboxUniqueName;

          $dispname = [Microsoft.Exchange.Management.RecipientTasks.EnableMailbox]::DiscoveryMailboxDisplayName;

          $dismbx = get-mailbox -Filter {name -eq $name} -IgnoreDefaultScope -resultSize 1;

          if( $dismbx -ne $null)

          {

          $srvname = $dismbx.ServerName;

          if( $dismbx.Database -ne $null -and $RoleFqdnOrName -like "$srvname.*" )

          {

          Write-ExchangeSetupLog -info "Setup DiscoverySearchMailbox Permission.";

          $mountedMdb = get-mailboxdatabase $dismbx.Database -status | where { $_.Mounted -eq $true };

          if( $mountedMdb -eq $null )

          {

          Write-ExchangeSetupLog -info "Mounting database before stamp DiscoverySearchMailbox Permission...";

          mount-database $dismbx.Database;

          }

          $mountedMdb = get-mailboxdatabase $dismbx.Database -status | where { $_.Mounted -eq $true };

          if( $mountedMdb -ne $null )

          {

          $dmRoleGroupGuid = [Microsoft.Exchange.Data.Directory.Management.RoleGroup]::DiscoveryManagement_InitInfo.WellKnownGuid;

          $dmRoleGroup = Get-RoleGroup -Identity $dmRoleGroupGuid -DomainController $RoleDomainController -ErrorAction:SilentlyContinue;

          if( $dmRoleGroup -ne $null )

          {

            trap [Exception]

            {

              Add-MailboxPermission $dismbx -User $dmRoleGroup.Name -AccessRights FullAccess -DomainController $RoleDomainController -ErrorAction SilentlyContinue;

              continue;

            }

            Add-MailboxPermission $dismbx -User $dmRoleGroup.Identity -AccessRights FullAccess -DomainController $RoleDomainController -WarningAction SilentlyContinue;

          }

          }

          }

          }