How To Fix E2556 - The namespace &1_* is already occupied in system &4 by &2 &3

SAP Error Message - Details

• Message type: E = Error

• Message class: E2 - DE Data Dictionary

• Message number: 556

• Message text: The namespace &1_* is already occupied in system &4 by &2 &3

What causes this issue?

You want to create the type group &V1&. However, there is already a
Dictionary object in the namespace of this type group. &V2& &V3& exists
globally in the SAP system &V4&.
Within a type group you can define any number of types whose names are
made up of the names of the type group, an underscore line, and the type
name.
There is the danger that a type defined in the type group matches the
name of a Dictionary object that already exists. Once the two dictionary
objects have been transported into the same system, the type group and
all dependent objects (programs, classes etc.) will be syntactically
incorrect.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

It is recommended that you use a different name for the type group.
Alternatively you can try to change the name of the other Dictionary
object.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message E2556 - The namespace &1_* is already occupied in system &4 by &2 &3 ?

  The SAP error message E2556 indicates that a namespace you are trying to use is already occupied in the system. This error typically occurs when you attempt to create or register an object (like a package, function module, or class) in a namespace that is already in use by another object.
  Cause:
  
  Namespace Conflict: The namespace you are trying to use (denoted as &1_* in the error message) is already occupied by another object, which is identified by &2 (the object type) and &3 (the name of the object).
  System-Specific: The error message also indicates the system (&4) where the conflict is occurring, which can be useful for identifying the environment you are working in.
  
  Solution:
  
  Check Existing Objects: Use transaction SE80 (Object Navigator) or SE11 (Data Dictionary) to check for existing objects in the namespace you are trying to use. Look for the object type and name mentioned in the error message.
  Choose a Different Namespace: If the namespace is already occupied, consider using a different namespace that is available and not in use.
  Delete or Modify Existing Objects: If you have the necessary permissions and it is appropriate to do so, you may consider deleting or modifying the existing object that is occupying the namespace. However, be cautious with this approach as it may affect other functionalities.
  Contact SAP Basis Team: If you are unsure about the existing objects or how to proceed, it may be best to consult with your SAP Basis team or system administrator for assistance.
  
  Related Information:
  
  Namespaces in SAP: Namespaces are used to organize and manage objects in SAP systems. They help avoid naming conflicts between different development objects.
  Development Guidelines: When developing in SAP, it is important to follow naming conventions and guidelines to avoid conflicts with existing objects.
  Transaction Codes: Familiarize yourself with relevant transaction codes like SE80 (Object Navigator), SE11 (Data Dictionary), and SE37 (Function Modules) to manage and investigate objects in the system.
  
  By following these steps, you should be able to resolve the E2556 error and successfully manage your namespaces in SAP.