Symptoms
When try to action the task via SmartAction, user will receive following response:-
The K2 server did not understand your response for the worklist item.
You may try one of the configured actions:
Or one of the standard actions:
* Redirect
* Delegate
* Sleep
This server accepts dates in the formats 'M/d/yyyy' and 'dddd, MMMM dd, yyyy', and times in the formats 'h:mm tt' and 'h:mm:ss tt'. Dates and times may be combined and a time zone may be specified using ' /-hh:mm'. For example 7/3/2015 5:43:31 PM 2:30 or 7/3/2015 or Friday, July 03, 2015.
Ensure that the serial number of the task is included in your reply. You can find this in the original notification or on your K2 Worklist.
Diagnoses
Initial checks reveal that this is only happen to a very specific process. So the cause of this issue should be within the process scope
Resolution
Turned out that it's due to "Make this action available without opening the work item" not turned on in Client Activity action outcome. Resolved after turn on that option and redeploy the process.
The default setting of that option is always true.
