How To Fix DNO021 - A notification with number &1 already exists

DNO021 - Overview

• Message type: E = Error

• Message class: DNO - Messages for General Notifications

• Message number: 021

• Message text: A notification with number &1 already exists

What causes this issue?

There is already a notification in the System with the number &1.

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?

Change your entry.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

DNO021 - Details

• The SAP error message DNO021 indicates that a notification with the specified number already exists in the system. This typically occurs when you attempt to create a new notification using a number that is already assigned to an existing notification.
  
  Cause:
  
  Duplicate Notification Number: The most common cause is that the notification number you are trying to use is already in use by another notification.
  Manual Entry Error: Users may inadvertently enter a notification number that has already been created.
  System Configuration: The system may be configured to allow manual entry of notification numbers, leading to potential conflicts.
  
  
  Solution:
  
  
  Check Existing Notifications: Before creating a new notification, check the existing notifications to see if the number you are trying to use is already assigned. You can do this by using transaction codes like IW21 (Create Notification) or IW22 (Change Notification) and searching for the notification number.
  
  
  Use Automatic Number Assignment: If your organization allows it, consider using