How To Fix WZ408 - The keys of the two objects involved are not compatible

SAP Error Message - Details

• Message type: E = Error

• Message class: WZ - Workflow: Model objects

• Message number: 408

• Message text: The keys of the two objects involved are not compatible

What causes this issue?

The business object and the change document object must have the same
keys. This is not the case with the two objects involved.

System Response

The combination of the two objects is rejected.

How to fix this error?

Choose another change document object and repeat the procedure.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message WZ408 - The keys of the two objects involved are not compatible ?

  SAP Error Message:
  
  WZ408 - The keys of the two objects involved are not compatible
  
  Cause:
  This error occurs when you try to perform an operation involving two objects (such as linking, comparison, or assignment) whose key fields do not match or are incompatible. In SAP, many objects (like business objects, table entries, or data structures) have key fields that uniquely identify them. If these keys differ in type, length, or structure, the system cannot process the operation, resulting in this error.
  Common scenarios include:
  
  Attempting to link two business objects with different key definitions.
  Trying to assign or compare objects where the key fields differ.
  Using function modules or BAPIs that expect compatible keys but receive mismatched objects.
  
  
  Solution:
  
  
  Check the Object Keys:
  
  Verify the key fields of both objects involved.
  Ensure that the key fields are of the same data type, length, and structure.
  
  
  
  Adjust the Objects or Code:
  
  Modify the code or configuration to ensure that only compatible objects are linked or compared.
  If you are developing or customizing, ensure that the key fields used in your logic match the expected keys.
  
  
  
  Use Correct Business Object Types:
  
  Confirm that the business objects or entities you are working with are designed to be linked or compared.
  Use the appropriate methods or BAPIs that handle the specific object types.
  
  
  
  Debugging:
  
  Use transaction SWO1 to check the business object definitions and their keys.
  Debug the program to see the exact values and types of the keys involved.
  
  
  
  Consult SAP Documentation:
  
  Look up the specific function module, BAPI, or method documentation to understand the expected key structures.
  
  
  
  
  Related Information:
  
  Transaction SWO1: Used to display and analyze business objects and their key definitions.
  Business Object Repository (BOR): Understanding the key structure of objects is crucial when working with BOR.
  BAPI and Function Module Documentation: Always check the interface documentation for key requirements.
  SAP Notes: Sometimes, specific SAP Notes address known issues related to object key incompatibility.
  
  
  Summary:
  WZ408 indicates a mismatch in the key fields of two objects involved in an operation. To resolve it, ensure that the keys are compatible in type and structure, adjust your code or configuration accordingly, and verify the business object definitions using SAP tools like SWO1.