How To Fix 5W123 - Prefix number &1 is not in the customer namespace

SAP Error Message - Details

• Message type: E = Error

• Message class: 5W - Messages for PD (Particularly Workflow)

• Message number: 123

• Message text: Prefix number &1 is not in the customer namespace

What causes this issue?

You have tried to create a prefix number that is not in the customer
namespace.

System Response

The entry cannot be created.

How to fix this error?

Please choose a prefix number between 900 and 999.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 5W123 - Prefix number &1 is not in the customer namespace ?

  The SAP error message 5W123 indicates that the prefix number specified (represented by &1) is not recognized as being part of the customer namespace. This typically occurs in the context of SAP development, particularly when dealing with objects like function modules, classes, or other development objects that require a specific naming convention.
  Cause:
  
  Incorrect Prefix: The prefix used in the object name does not match the defined customer namespace. In SAP, customer namespaces are usually defined by a specific range of characters (e.g., Z or Y).
  Namespace Configuration: The system may not be configured correctly to recognize the customer namespace, or the prefix may not have been properly registered.
  Development Object Naming: When creating new development objects, the naming convention must adhere to the rules set for the customer namespace.
  
  Solution:
  
  Check Prefix: Verify that the prefix you are using is indeed part of the customer namespace. If you are using a prefix that is not allowed, change it to a valid one (e.g., Z or Y).
  Namespace Registration: If you believe the prefix should be valid, check with your SAP Basis team to ensure that the namespace has been properly registered and configured in the system.
  Use Correct Naming Convention: When creating new objects, always follow the naming conventions set by your organization. If you are unsure, consult your development guidelines or speak with a senior developer.
  Transport Requests: If this error occurs during a transport, ensure that the transport request is correctly set up and that all objects are in the appropriate namespace.
  
  Related Information:
  
  Customer Namespace: In SAP, customer namespaces are designated for custom development to avoid conflicts with standard SAP objects. The most common prefixes are Z and Y.
  Development Guidelines: Organizations often have specific guidelines for naming conventions and object creation. Familiarize yourself with these to avoid similar issues in the future.
  SAP Notes: Check SAP Notes for any updates or specific fixes related to this error message, as there may be patches or recommendations from SAP.
  
  If the issue persists after following these steps, consider reaching out to your SAP support team for further assistance.