How To Fix M2020 - Field catalog already exists

SAP Error Message - Details

• Message type: E = Error

• Message class: M2 - LIS: Generating and updating info structures

• Message number: 020

• Message text: Field catalog already exists

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message M2020 - Field catalog already exists ?

  The SAP error message M2020, which states "Field catalog already exists," typically occurs in the context of SAP's Material Management (MM) module, particularly when dealing with reports or ALV (ABAP List Viewer) grids. This error indicates that there is an attempt to create a field catalog that has already been defined in the program or report.
  Cause:
  The error is usually caused by one of the following reasons:
  
  Duplicate Field Catalog Definition: The field catalog is being defined multiple times in the same program or report.
  Improper Handling of Field Catalog: The field catalog is not being cleared or reset before being redefined, leading to conflicts.
  Program Logic Issues: The logic in the program may inadvertently lead to the same field catalog being created multiple times.
  
  Solution:
  To resolve the M2020 error, you can take the following steps:
  
  
  Check for Duplicate Definitions:
  
  Review the code to ensure that the field catalog is defined only once. Look for any duplicate FIELD-CATALOG definitions.
  
  
  
  Clear the Field Catalog:
  
  Before redefining the field catalog, ensure that it is cleared. You can do this by using the CLEAR statement or by reinitializing the field catalog variable.
  
  Example:
  CLEAR lt_fieldcat. " lt_fieldcat is the field catalog table
  
  
  Use Proper Scope:
  
  If the field catalog is defined in a subroutine or method, ensure that it is not being reused inappropriately across different calls.
  
  
  
  Debugging:
  
  Use the debugger to trace the execution of the program and identify where the field catalog is being defined multiple times.
  
  
  
  Review Documentation:
  
  Check the SAP documentation or notes related to the specific report or program you are working with for any known issues or recommendations.
  
  
  
  Related Information:
  
  ALV Reports: The error is commonly encountered in ALV report programming, where field catalogs are used to define the structure of the output.
  Field Catalog Structure: The field catalog is typically defined as an internal table of type LVC_S_FCAT or similar, which contains the metadata for the fields to be displayed in the report.
  SAP Notes: Check SAP Notes for any specific patches or updates related to the error message M2020, as there may be known issues or fixes provided by SAP.
  
  By following these steps, you should be able to resolve the M2020 error and ensure that your field catalog is defined correctly without duplication.