Execute Workflow Task Action for Workflow

Hello,

I am using MDM Java APIs to retrieve Workflow Tasks for Records and want to set the Workflow Task Action to SEND_NEXT_STEP. . I am using the following link for the same:

http://help.sap.com/saphelp_mdm71/helpdata/en/01/e125e63aac46c48b130b63b0043569/content.htm

But when I set the Action to the ExecuteWorkflowTasksAction Command and execute it , it says that the Action is disabled , so how can I enable the action and perform the same.?

Any help would be highly appreciated.

Thanks