How To Fix WD503 - New task selected, enter expression for task

SAP Error Message - Details

• Message type: E = Error

• Message class: WD - Workflow definition

• Message number: 503

• Message text: New task selected, enter expression for task

What causes this issue?

You have overwritten task &v1& with &v2&.
In addition, you have set the indicator <LS>task determined by
expression</> in order to determine the task dynamically at runtime.
If the task you have entered in the <ZH>control</> window is different
in the interface from the task which is determined dynamically at
runtime, there may be problems with the workflow execution.

System Response

The system informs you that the task to be executed has been determined
dynamically at runtime.

How to fix this error?

Check whether the new task &v2& has the same parameters as task &v1&,
otherwise the binding will not function properly at runtime.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WD503 - New task selected, enter expression for task ?

  The SAP Web Dynpro error message WD503 New task selected, enter expression for task typically occurs when you are working with task nodes in a Web Dynpro component and the system expects an expression to be entered for the task, but none has been provided.
  
  Cause:
  
  In a Web Dynpro component, when you define a task node in the component controller or in a window, you need to specify the task that the node should execute.
  This error occurs if you select a new task node but do not enter or assign the required expression or task name.
  Essentially, the system is prompting you to provide the expression that defines which task the node should trigger.
  
  
  Explanation:
  
  A task node in Web Dynpro represents a unit of work or a method that can be executed.
  When you add a new task node, you must bind it to a task (method) by entering an expression that points to the task.
  If this expression is missing or incomplete, the system cannot determine what the task node should do, hence the error.
  
  
  Solution:
  
  
  Enter the Expression for the Task:
  
  In the Web Dynpro component editor, locate the task node that you have just created or selected.
  In the properties pane, find the field labeled Task or Expression.
  Enter the correct expression that points to the task you want to execute. This is usually something like:
  wdThis->your_task_name
  where your_task_name is the name of the task method defined in your component controller.
  
  
  
  
  Verify the Task Exists:
  
  Make sure the task you are referencing actually exists in the component controller or the context where you are trying to use it.
  If the task does not exist, create it first.
  
  
  
  Save and Activate:
  
  After entering the correct expression, save and activate your component.
  The error should no longer appear.
  
  
  
  
  Additional Information:
  
  This message is a prompt rather than a system error, guiding you to complete the configuration.
  Task nodes are part of the Web Dynpro component’s flow logic, and proper binding is essential for the application to work correctly.
  If you are new to Web Dynpro, familiarize yourself with the concepts of component controllers, task nodes, and flow logic.
  Refer to SAP documentation on Web Dynpro for ABAP for detailed guidance on task nodes and flow logic.
  
  
  Summary:
  
  
  
  Aspect
  Details
  
  
  
  
  Cause
  Task node created/selected without entering the required expression for the task.
  
  
  Solution
  Enter the correct expression for the task node, e.g., wdThis->task_name.
  
  
  Related Info
  Task nodes represent executable tasks in Web Dynpro; expression binding is mandatory.
  
  
  
  
  If you need help with the exact syntax or where to enter the expression, please specify your SAP GUI version or Web Dynpro development environment.