Symptoms

"If a Workflow activity is specified" condition isn't met when using 'SN' parameter in a Form.

 

Diagnoses

There are two naming conventions for passing a Process serial number to a Form, SerialNo and SN, which come from Designer and K2 Studio respectively. Using 'SN' will requires an 'Open a Worklist Item' action to fire before the "If a Workflow activity is specified" condition can be used, while 'SerialNo' does not.
 

Resolution

Call the 'Open a Worklist Item' action in your Form Initializing rule. Any subsequent use of the "If a Workflow activity is specified" condition will be successful.

Alternatively, you can manually build the Task Item URL with the following structure:

".../FormName/?SerialNo=NProcessID]_DActivityInstanceDestID]"

using 'Process Instance -> ID' and 'Activity Destination Instance -> ID' as its fields.