How To Fix GB129 - Substitution name must begin with a letter

GB129 - Overview

• Message type: E = Error

• Message class: GB - Messages used by the Boolean code generator

• Message number: 129

• Message text: Substitution name must begin with a letter

What causes this issue?

The name of the substitution must begin with a letter (and not with a
number). You can use the following letters:
ABCDEFGHIJKLMNOPQRSTUVWXYZ

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?

Re-enter the name of the substitution.

Error message extract from SAP system. Copyright SAP SE.

GB129 - Details

• The SAP error message GB129, which states "Substitution name must begin with a letter," typically occurs in the context of SAP's substitution functionality, often used in financial or controlling modules. This error indicates that the name you are trying to use for a substitution does not conform to the naming conventions required by SAP.
  
  Cause:
  
  Invalid Naming Convention: The substitution name you are trying to create or use does not start with a letter. SAP requires that all substitution names begin with an alphabetic character (A-Z).
  Typographical Error: There may be a typographical error in the name you are entering, such as starting with a number or a special character.
  Copy-Paste Issues: If you copied the name from another source, it might contain hidden characters or spaces that are not visible.
  
  
  Solution:
  
  Check the Name: Ensure that the substitution name you are entering starts with a letter. For example, instead of "1Substitution", use "Substitution1".
  Remove Special Characters: