Today I encountered a strange issue when trying to publish a basic SharePoint 2013 Workflow that has a Start Task Process action in it.
The error I received was the following:
Cannot set unknown member 'CompositeTask.PreserveIncompleteTasks'. HTTP headers received from the server Microsoft.Workflow.Client.ActivityValidationException: Workflow XAML failed validation due to the following errors: Cannot set unknown member 'CompositeTask.PreserveIncompleteTasks'. HTTP headers received from the server - ActivityId: 51341428-f7a1-4856-8303-fcbc699335ea. NodeId: SPSRV. Scope: /SharePoint/default/8f0c9dfe-6f01-499c-a356-a417da9b39b4/53d5e7f1-0360-4909-8997-71eaf26b140d. Client ActivityId : a1627f9c-bdfc-80a3-b6fd-cf246a4e8993. ---> System.Net.WebException: The remote server ret
Checking the logs didn't provide any useful clue. Digging the net I found a post (linked at the bottom) that suggested re-registering the SharePoint 2013 Workflow Service. So I did that.
Register-SPWorkflowService -SPSite https://portal.mydomain.net -WorkflowHostUri https://spsrv:12290 -Force
Question: Will this command affect my currently running workflows?
Answer: No, all workflows will continue running smoothly, even if they are in progress, paused or waiting for an item to change. Tested.