“Invalid return type for custom action” from Workflow Action Script

The following error is thrown when triggering a Workflow Action Script.

 Notice:  

  ■Invalid return type for custom action

Solution

Above error is returned when the Workflow Action has a value selected under Parameters> Store Results In but does not have a return value inside the Workflow Action script.

Sample:

function workflowAction() {

var recordnumber = nlapiGetRecordId();

    //Commenting out below line will cause the error.

//return recordnumber;

}

Store Result In = Freeform Text Field (State) (Type = Free-Form Text)

To avoid the error, make sure that a return line is added and it matches the field Type of the field under Store Results In.