How To Fix KW157 - Choose "X" or " " (space) as an indicator

KW157 - Overview

• Message type: E = Error

• Message class: KW - CO-ABC Activity-Based Costing

• Message number: 157

• Message text: Choose "X" or " " (space) as an indicator

What causes this issue?

The field you chose is an indicator ("check box", "check mark"),
representing one of two situations: (marked/not marked, chosen/not
chosen).
For these fields only one convention applies for entry values:
either 'X' (marked) or ' ' (space/unmarked).
You entry ('&v1&') is not allowed.

How to fix this error?

Please enter 'X' (upper case) or ' ' (space).

Error message extract from SAP system. Copyright SAP SE.

KW157 - Details

• The SAP error message KW157, which states "Choose 'X' or ' ' (space) as an indicator," typically occurs in the context of SAP's configuration or data entry processes, particularly when dealing with indicators that require a binary choice (i.e., either 'X' for yes/true or a space for no/false).
  
  Cause:
  This error arises when a user attempts to save or process data in a field that expects a specific indicator value, but the value provided does not meet the expected criteria. The system is prompting the user to select either 'X' (indicating a positive response or selection) or a blank space (indicating a negative response or no selection).
  
  Solution:
  To resolve this error, follow these steps:
  
  
  Check the Field: Identify the field that is causing the error. Ensure that you are entering either 'X' or leaving the field blank (space).
  
  
  Correct Input: If you have entered any other character or value, replace it with 'X' or a