How To Fix TR420 - Packages must begin with A-Z, &1, or a namespace prefix

SAP Error Message - Details

• Message type: E = Error

• Message class: TR - Change and Transport System

• Message number: 420

• Message text: Packages must begin with A-Z, &1, or a namespace prefix

What causes this issue?

The name of the package is invalid, since it does not start with A-Z,
$, or with a valid namespace prefix.

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?

Choose a valid name for the package.
You can display a list of the namespace prefixes in the SAP System with
the Transport Organizer tools (transaction <DS:TRAN.SE03>SE03</>).
Choose <LS>Objects</> -> <LS>Namespace Information System</>, and then
<LS>Select namespace</>.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message TR420 - Packages must begin with A-Z, &1, or a namespace prefix ?

  The SAP error message TR420 indicates that there is an issue with the naming convention of a transport package. Specifically, it states that the package name must begin with a letter (A-Z), a number (0-9), or a namespace prefix. This error typically occurs when you are trying to create or transport a package that does not adhere to these naming rules.
  Cause:
  
  Invalid Package Name: The package name you are trying to use starts with an invalid character (e.g., special characters or spaces).
  Namespace Issues: If you are using a namespace, it may not be correctly defined or formatted.
  Typographical Errors: There may be a typo in the package name that causes it to not conform to the required format.
  
  Solution:
  
  
  Check Package Name: Ensure that the package name starts with a letter (A-Z), a number (0-9), or a valid namespace prefix. For example, valid package names could be Z_MY_PACKAGE, Y_PACKAGE1, or A1_PACKAGE.
  
  
  Correct Naming Convention: If the package name does not meet the criteria, rename the package to conform to the naming conventions. You can do this in the SAP GUI by navigating to the relevant transaction (e.g., SE80 for Object Navigator) and modifying the package name.
  
  
  Use Namespace Prefix: If you are developing custom objects, consider using a namespace prefix (e.g., Z_ or Y_) to avoid conflicts with standard SAP packages.
  
  
  Review Transport Request: If the error occurs during a transport request, check the transport request details to ensure that all included objects are correctly named.
  
  
  Consult Documentation: Refer to SAP documentation or guidelines regarding naming conventions for packages and transport requests to ensure compliance.
  
  
  Related Information:
  
  SAP Naming Conventions: Familiarize yourself with SAP's naming conventions for packages, which typically require that they start with a letter or a valid namespace.
  Transport Management System (TMS): Understanding how the TMS works can help you manage transport requests and packages more effectively.
  SAP Notes: Check for any relevant SAP Notes that may provide additional insights or updates regarding this error message.
  
  By following these steps, you should be able to resolve the TR420 error and successfully create or transport your package.