How To Fix 00125 - No field defined for the function code

00125 - Overview

• Message type: E = Error

• Message class: 00 -

• Message number: 125

• Message text: No field defined for the function code

What causes this issue?

The function code field (OK code field) has not been defined on this
screen. If the user selects an application function (not a system
function), the system usually provides it in the function code field
(OK code field) as well as in SY-UCOMM. This is no longer possible.

System Response

The system is unable to inform the application of the current function
code. The application should not use field SY_COMM. This field always
contains the code of the last function chosen, which is not always
identical to the application-relevant code.

How to fix this error?

You should always define a field for the function code on every screen.
The Screen Painter always proposes such a field (OK category), you only
need to assign a name and include the definition in the ABAP program.

Error message extract from SAP system. Copyright SAP SE.

00125 - Details

• The SAP error message "00125 No field defined for the function code" typically occurs when there is an issue with the configuration of a screen or a transaction in SAP. This error indicates that the system is unable to find a field that corresponds to the function code being executed. Here’s a breakdown of the cause, potential solutions, and related information:
  
  Cause:
  
  Missing Field Definition: The function code being called does not have a corresponding field defined in the screen or program.
  Incorrect Screen Configuration: The screen might not be properly configured to handle the function code, leading to the absence of the required field.
  Custom Development Issues: If there are custom programs or enhancements, they may not have been implemented correctly, leading to this error.
  Transport Issues: If the configuration or development has been transported from one environment to another (e.g., from development to production), there may be inconsistencies.
  
  Solutions:
  
  
  Check Screen Configuration:
  
  Go to the screen