How To Fix CL179 - Class type "&" has exactly one object type: "&"

SAP Error Message - Details

• Message type: E = Error

• Message class: CL - Classification

• Message number: 179

• Message text: Class type "&" has exactly one object type: "&"

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 CL179 - Class type "&" has exactly one object type: "&" ?

  The SAP error message CL179 indicates that there is an issue with the class type definition in the ABAP Object-Oriented programming environment. Specifically, the message states that the class type you are trying to define or work with has exactly one object type associated with it, which can lead to confusion or conflicts in the system.
  Cause:
  The error typically arises in the following scenarios:
  
  Class Definition Issues: You may be trying to define a class that is expected to have multiple object types, but the system recognizes only one.
  Inheritance Problems: If you are trying to inherit from a class that has a specific object type, and your class definition does not align with the expected structure, this error can occur.
  Incorrect Class Type Usage: You might be using a class type in a way that is not supported by the system, such as trying to instantiate or reference it incorrectly.
  
  Solution:
  To resolve the CL179 error, consider the following steps:
  
  
  Check Class Definition: Review the class definition to ensure that it is correctly defined and that it aligns with the expected structure. Make sure that the class is not mistakenly defined as a single object type when it should support multiple types.
  
  
  Review Inheritance: If your class is inheriting from another class, ensure that the parent class is defined correctly and that the inheritance structure is valid. Check for any inconsistencies in the class hierarchy.
  
  
  Adjust Object Types: If the class is intended to have multiple object types, you may need to adjust the class definition to accommodate this. This could involve modifying the class attributes or methods to support the required functionality.
  
  
  Check for Conflicts: Look for any naming conflicts or issues with other classes that may be causing the system to misinterpret the class type.
  
  
  Consult Documentation: Refer to SAP documentation or community forums for additional insights or similar cases. Sometimes, specific versions of SAP may have known issues or peculiarities that can lead to this error.
  
  
  Debugging: If you have access to debugging tools, you can step through the code to identify where the error is being triggered and gather more context about the issue.
  
  
  Related Information:
  
  SAP Notes: Check SAP Notes for any updates or patches related to this error message. SAP frequently releases notes that address specific issues or provide guidance on best practices.
  ABAP Documentation: Familiarize yourself with the ABAP Object-Oriented programming concepts, especially regarding class definitions, inheritance, and object types.
  Community Forums: Engage with the SAP community through forums like SAP Community or Stack Overflow, where you can ask questions and share experiences with other developers.
  
  By following these steps, you should be able to identify the root cause of the CL179 error and implement a suitable solution.