Exception error when using Powershell to start a workflow on SharePoint 2010 on an item

Question

I am very new to powershell. I am trying to use it to start a (send Document Set to repository) workflow on selected Document Sets in a library. The workflow worked when I used it manually on one document set at a time, but when I ran the script, I came across this error:

*

Exception calling "StartWorkflow" with "4" argument(s): "Attempted to perform a unauthorized operation." At line:3 char:32 + $wf=$manager.StartWorkflow <<<< ($item,$assoc,$data,$true) + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorID : DotNetMethodException*

# URL of the Site
$weburl = "myURL"  
$web = Get-SPWeb $weburl

$manager = $web.Site.WorkFlowManager

# Name of the list
 $list = $web.Lists["Style"]

# Name of the Workflow
$assoc = $list.WorkflowAssociations| where {$_.Name -eq "copyStyleToSomewhere"}

$data = $assoc.AssociationData
$listItems = $list.Items

foreach($item in $listItems){
   if($item.Name -match "style1234"){
   $wf = $manager.StartWorkFlow($item,$assoc,$data,$true)
 }
}

$manager.Dispose()
 $web.Dispose()

I am not sure what the problem is. Help is much appreciated. Thank you.

Answer 1

I finally realised the error message was because my admin account did not have enough rights to run the script. I've been told the clue was the "unauthorized operation..." part of the error message. When I logged in as the farm account, it worker perfectly.