How To Fix /CFG/DB198 - Class &1 doesn't implement interface &2 , Invalid class

SAP Error Message - Details

• Message type: E = Error

• Message class: /CFG/DB -

• Message number: 198

• Message text: Class &1 doesn't implement interface &2 , Invalid class

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message /CFG/DB198 - Class &1 doesn't implement interface &2 , Invalid class ?

  The SAP error message /CFG/DB198 Class &1 doesn't implement interface &2, Invalid class typically indicates that there is a problem with a class in the SAP system that is expected to implement a specific interface but does not. This can occur in various contexts, such as when working with Business Object Processing Framework (BOPF), Business Workflow, or other object-oriented programming scenarios in SAP.
  Cause:
  
  
  Class Definition Issue: The class specified in the error message (&1) does not implement the interface specified (&2). This could be due to:
  
  The class was not properly defined to implement the required interface.
  The interface has been changed or deleted, and the class is no longer compliant.
  There may be a typo in the class or interface name.
  
  
  
  Transport Issues: If the class or interface was recently transported from another system, it may not have been transported correctly, leading to inconsistencies.
  
  
  Version Mismatch: The class might be an older version that does not implement the latest version of the interface.
  
  
  Solution:
  
  
  Check Class Implementation:
  
  Go to the ABAP Workbench (transaction SE80) and check the class definition. Ensure that the class implements the specified interface correctly.
  If the class is missing the implementation of the interface methods, you will need to add them.
  
  
  
  Check Interface Definition:
  
  Verify that the interface exists and is correctly defined. You can do this in SE80 or SE11.
  
  
  
  Re-implement the Interface:
  
  If the class is supposed to implement the interface, you may need to re-implement it. This can be done by editing the class and ensuring that it includes the necessary methods defined in the interface.
  
  
  
  Transport Consistency:
  
  If the issue arose after a transport, check the transport logs and ensure that all necessary objects were transported correctly. You may need to re-transport the class or interface.
  
  
  
  Check for Dependencies:
  
  Ensure that there are no missing dependencies that the class or interface relies on. This includes checking for other classes or interfaces that may be required.
  
  
  
  Debugging:
  
  If the issue persists, consider debugging the code that is triggering the error to get more context on when and why the error occurs.
  
  
  
  Related Information:
  
  Transaction Codes: Use SE80 (Object Navigator) to check class and interface definitions, SE11 (Data Dictionary) for interface details, and SE37 (Function Module) if the error is related to function modules.
  Documentation: Review SAP documentation related to the specific framework or technology you are working with (e.g., BOPF, Workflow).
  SAP Notes: Check the SAP Support Portal for any relevant SAP Notes that might address this specific error or provide additional guidance.
  
  If you continue to experience issues after following these steps, consider reaching out to your SAP Basis or Development team for further assistance.