Unable to cancel a 2010 workflow in SharePoint 2013 using JSOM

Question

The following code works well in my test environment, but not in my UAT environment. Both are running SharePoint 2013.

var ctx = new SP.ClientContext.get_current();
var wfServicesMgr = new SP.WorkflowServices.WorkflowServicesManager(ctx, ctx.get_web());
var wfInteropService = wfServicesMgr.getWorkflowInteropService();
wfInteropService.cancelWorkflow(workflowInstanceId);
ctx.executeQueryAsync(function(source, args){
    // Works in one enviroment
}, function (source, args) {
    // Results in the following message in another environment
    //    Cannot invoke method or retrieve property from null object. Object returned by the following call stack is null. 
    //    "GetWorkflowInteropService new Microsoft.SharePoint.WorkflowServices.WorkflowServicesManager()"
    var msg = args.get_message();
});

As mentioned in the comments above, the error I see in UAT is:

Cannot invoke method or retrieve property from null object. Object returned by the following call stack is null. "GetWorkflowInteropService new Microsoft.SharePoint.WorkflowServices.WorkflowServicesManager()"

Any ideas? I don't think I need to worry about workflow configuration in either environment since these are 2010 workflows and not 2013 workflows.

Answer 1

The answer for me was to make sure the workflow manager was installed properly in the environment. Even though I was trying to terminate a 2010 WF, we need the WF manager running for this code to work, it appears.