How To Fix W8191 - Field or field value restrictions for "change" event only

W8191 - Overview

• Message type: E = Error

• Message class: W8 - Workflow: Expressions, data flow

• Message number: 191

• Message text: Field or field value restrictions for "change" event only

What causes this issue?

It is only worth defining field and field value restrictions if the
event is created when a "change" occurs.

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?

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message W8191 - Field or field value restrictions for "change" event only ?

  Certainly! Here's a detailed explanation for the SAP error message W8191: Field or field value restrictions for "change" event only:
  
  Error Message
  W8191: Field or field value restrictions for "change" event only
  
  Cause
  This warning message occurs when you try to apply field or field value restrictions in a context other than the "change" event in SAP. In SAP, certain field restrictions or validations are only allowed or meaningful during the change event of a screen or a transaction.
  
  The "change" event refers to the point in the processing where the user has made changes to the screen fields, and the system is validating or restricting input values.
  If you attempt to apply these restrictions during other events (like PBO - Process Before Output, PAI - Process After Input, or other custom events), SAP issues this warning because the restrictions are only valid or supported during the change event.
  
  
  When does this happen?
  
  When you define field or