How To Fix WS_TOOL857 - Function &1: &2 parameter &3 was changed to "not optional"

SAP Error Message - Details

• Message type: E = Error

• Message class: WS_TOOL - Message Class for Web Services and Virtual Endpoints

• Message number: 857

• Message text: Function &1: &2 parameter &3 was changed to "not optional"

Self-Explanatory Message

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• What is the cause and solution for SAP error message WS_TOOL857 - Function &1: &2 parameter &3 was changed to "not optional" ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  WS_TOOL857 Function &1: &2 parameter &3 was changed to "not optional"
  
  Meaning / Cause:
  This message occurs when a function module's interface parameter, which was previously defined as optional, has been changed to not optional (mandatory). In other words, the parameter that could be omitted before now must be supplied when calling the function module.
  This typically happens during transport or import of function module changes, or when the function module interface is modified in the development system and then transported to other systems.
  
  Why is this a problem?
  
  Changing a parameter from optional to mandatory is a non-compatible interface change.
  Existing programs or function calls that do not supply this parameter will now fail or behave unexpectedly.
  SAP tools (like the Function Builder or transport tools) detect this change and issue this warning/error to alert developers/administrators.
  
  
  Solution / How to fix:
  
  
  Review the change:
  
  Confirm that the change from optional to mandatory is intentional and necessary.
  Check the function module interface in SE37 or SE80.
  
  
  
  Adjust calling programs:
  
  Ensure all programs or function calls that use this function module now supply the parameter.
  Modify the calling code to pass the required parameter.
  
  
  
  Transport consistency:
  
  If the change was transported, verify that all dependent systems and programs are updated accordingly.
  Communicate the interface change to all developers and users.
  
  
  
  If the change was unintentional:
  
  Revert the parameter back to optional if possible.
  Re-transport the corrected function module.
  
  
  
  Testing:
  
  Thoroughly test all affected programs to ensure they work with the new mandatory parameter.
  
  
  
  
  Additional Information:
  
  Parameter optionality is defined in the function module interface under the parameter properties.
  Changing parameter optionality is considered a non-compatible change and should be handled carefully.
  SAP recommends avoiding such changes in productive systems without proper impact analysis.
  This message is informational but indicates a potential runtime problem if not addressed.
  
  
  Summary:
  
  
  
  Aspect
  Description
  
  
  
  
  Cause
  A function module parameter was changed from optional to mandatory.
  
  
  Effect
  Calls to the function module must now supply this parameter; otherwise, errors may occur.
  
  
  Solution
  Update all calling programs to supply the parameter or revert the change if unintentional.
  
  
  Tools
  Use SE37/SE80 to check and modify function module interface; check transports and dependencies.
  
  
  
  
  If you want, I can help you with the exact steps to check or modify the function module interface or update calling programs. Just let me know!