How To Fix FDT_CORE320 - Call to class &1 is illegal

SAP Error Message - Details

• Message type: E = Error

• Message class: FDT_CORE - Formula & Derivation Tool: Core

• Message number: 320

• Message text: Call to class &1 is illegal

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.

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Smart SAP Assistant

• What is the cause and solution for SAP error message FDT_CORE320 - Call to class &1 is illegal ?

  The SAP error message FDT_CORE320: Call to class &1 is illegal typically occurs in the context of SAP's Field Data Tool (FDT) or when working with custom classes in ABAP. This error indicates that there is an attempt to call a class that is either not defined, not accessible, or not properly instantiated.
  Causes:
  
  Class Not Found: The specified class does not exist in the system or is misspelled.
  Access Issues: The class may not be accessible due to visibility restrictions (e.g., it is declared as private or protected).
  Namespace Issues: The class might be in a different namespace that is not properly referenced.
  Incorrect Instantiation: The class might not be instantiated correctly, leading to an illegal call.
  Transport Issues: If the class was recently transported, it may not have been activated in the target system.
  
  Solutions:
  
  Check Class Existence: Verify that the class specified in the error message exists in the system. You can do this by using transaction SE24 (Class Builder) to search for the class.
  Check Spelling and Case: Ensure that the class name is spelled correctly and that the case matches, as ABAP is case-sensitive.
  Review Access Modifiers: Check the visibility of the class and its methods. If the class is private or protected, ensure that you are calling it from an appropriate context.
  Namespace Verification: Ensure that the class is in the correct namespace and that you are using the correct prefix if applicable.
  Instantiate Correctly: If you are trying to call a method of the class, ensure that you have instantiated the class correctly using the CREATE OBJECT statement.
  Transport Activation: If the class was recently transported, ensure that it has been activated in the target system. You can check this in transaction SE80 or SE24.
  Debugging: If the issue persists, consider debugging the code to trace where the illegal call is being made and gather more context about the error.
  
  Related Information:
  
  Transaction Codes: SE24 (Class Builder), SE80 (Object Navigator), SE37 (Function Module), SE11 (Data Dictionary).
  Documentation: Refer to SAP Help documentation for Field Data Tool and ABAP programming guidelines.
  SAP Notes: Check SAP Notes for any known issues or patches related to the error message FDT_CORE320.
  
  If the problem continues after trying the above solutions, consider reaching out to your SAP Basis or ABAP development team for further assistance.