Powershell parsing parsing error ".*\((?KB\d{6,7})\)" - Unrecognized grouping construct - regex

Question

Hi I'm trying to play with windows updates with PowerShell script, the script works fine but before results it through parsing error.
my script
$Session = New-Object -ComObject Microsoft.Update.Session
$Searcher = $Session.CreateUpdateSearcher()
$HistoryCount = $Searcher.GetTotalHistoryCount()
# http://msdn.microsoft.com/en-us/library/windows/desktop/aa386532%28v=vs.85%29.aspx
$Searcher.QueryHistory(0,$HistoryCount) | ForEach-Object -Process {
$Title = $null
if($_.Title -match "\(KB\d{6,7}\)"){
# Split returns an array of strings
$Title = ($_.Title -split '.*\((?KB\d{6,7})\)')[1]
}else{
$Title = $_.Title
}
# http://msdn.microsoft.com/en-us/library/windows/desktop/aa387095%28v=vs.85%29.aspx
$Result = $null
Switch ($_.ResultCode)
{
0 { $Result = 'NotStarted'}
1 { $Result = 'InProgress' }
2 { $Result = 'Succeeded' }
3 { $Result = 'SucceededWithErrors' }
4 { $Result = 'Failed' }
5 { $Result = 'Aborted' }
default { $Result = $_ }
}
New-Object -TypeName PSObject -Property #{
InstalledOn = Get-Date -Date $_.Date;
Title = $Title;
Name = $_.Title;
Status = $Result
}
} | Sort-Object -Descending:$true -Property nInstalledO |
Select-Object -Property * -ExcludeProperty Name | Format-Table -AutoSize -Wrap
above script works fine but before results it shows some parsing error at line
error:
parsing ".*\((?KB\d{6,7})\)" - Unrecognized grouping construct.
At B:\Clients\SirAhmad\check-updates-history.ps1:9 char:9
+ $Title = ($_.Title -split '.*\((?KB\d{6,7})\)')[1]
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : OperationStopped: (:) [], ArgumentException
+ FullyQualifiedErrorId : System.ArgumentException
at line
$Title = ($_.Title -split '.*\((?KB\d{6,7})\)')[1]
Looks regx issues.
Can someone help me out to indicate what is the issue with regix?