Workflow displaying "This task is currently locked by a running workflow and cannot be edited"

When you try to change the status of Task List in SharePoint from Inprogress to Complete, you will be greeted with a good error message "Workflow displaying "This task is currently locked by a running workflow and cannot be edited".

 

Powershell commands to unlock all the task items. 

 

$web=$site.OpenWeb()

$web.url

$i=0

foreach($list in $web.lists)

{

foreach($item in $list.items | where

{$_[[Microsoft.SharePoint.SPBuiltInFieldId]::WorkFlowVersion] -ne 1})

{

if($item["Status"] -eq "In Progress")

{

$item[[Microsoft.SharePoint.SPBuiltInFieldId]::WorkFlowVersion]=1;

$item.Update()

$i++

}

}

}

$web.dispose()

$site.dispose()

 

Here Workflow version has to be at one to unlock all the workflow items.