How To Fix AD211 - Structure type 'HEAD' can be used only once

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 211

• Message text: Structure type 'HEAD' can be used only once

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message AD211 - Structure type 'HEAD' can be used only once ?

  The SAP error message AD211, which states "Structure type 'HEAD' can be used only once," typically occurs in the context of ABAP programming, particularly when dealing with data structures and internal tables. This error indicates that the structure type 'HEAD' is being used multiple times in a way that is not allowed.
  Cause:
  
  Duplicate Declaration: The structure type 'HEAD' has been declared more than once in the same context, such as in a program or a function module.
  Incorrect Use in Internal Tables: If you are trying to define an internal table or a work area using the same structure type multiple times, it can lead to this error.
  Scope Issues: The structure might be defined in a way that it is not allowed to be reused in the same scope.
  
  Solution:
  
  Check Declarations: Review your code to ensure that the structure 'HEAD' is declared only once. If you need to use it multiple times, consider using a different name for the new structure or using a reference to the existing structure.
  Use of Types: If you need to create multiple instances of a structure, consider using a type declaration (e.g., TYPES: BEGIN OF head_type, ... END OF head_type.) and then use this type to declare your internal tables or work areas.
  Refactor Code: If the structure is being used in multiple places, refactor your code to avoid redundancy. You can create a common include or a global type definition that can be reused.
  Check for Includes: If you are using includes, ensure that the structure is not being included multiple times in the same program or function module.
  
  Related Information:
  
  ABAP Data Dictionary: Understanding how to manage data types and structures in the ABAP Data Dictionary can help prevent such issues.
  Documentation: Refer to SAP documentation on data types and structures for best practices in defining and using them.
  Debugging: Use the ABAP debugger to trace where the structure is being declared and used to identify the source of the error.
  
  By following these steps, you should be able to resolve the AD211 error and ensure that your ABAP code adheres to the structure usage rules in SAP.