Symptoms

I'm making a call from VB (C_) using WorklistNavigationServiceClient.ExecuteActionByWorklistItem(workListItem, "Complete", False) but it returns the message
"Action 'Complete' not found".
I see that my Workflow has an action called Complete but don't know how to see what I might be doing wrong... Can someone look over my shoulder and help me see how to debug this?
 

Diagnoses

Reviewing your custom application debug log, we found that the process tried to action the task using K2 Service account. We then reviewed your process design for that activity and noticed that the destination rule was set to a group that K2 Service account is not a member of
 

Resolution

After we changed the destination rule for that activity to K2 Service account and redeployed the process, the application was able to action the task successfully.