How To Fix AD420 - No change to the key field number

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 420

• Message text: No change to the key field number

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message AD420 - No change to the key field number ?

  The SAP error message AD420 ("No change to the key field number") typically occurs in the context of data management or when working with certain SAP transactions that involve key fields, such as when trying to modify or update records in a database table.
  Cause:
  The error message AD420 indicates that an attempt was made to change a key field in a way that is not allowed. Key fields are critical in database tables as they uniquely identify records. If you try to change a key field to a value that does not conform to the existing structure or if the system detects that no actual change has been made to the key field, this error will be triggered.
  Common Scenarios:
  
  Attempting to change a key field to the same value: If you are trying to update a key field but the new value is the same as the existing value, the system will not allow this change.
  Incorrect data entry: If the data being entered does not meet the criteria for the key field (e.g., length, format).
  Database constraints: There may be constraints in the database that prevent changes to key fields under certain conditions.
  
  Solution:
  To resolve the AD420 error, consider the following steps:
  
  
  Check the Key Field Value: Ensure that you are trying to change the key field to a different value. If the value is the same as the existing one, no change is necessary, and you can skip the update.
  
  
  Review Data Entry: Make sure that the data you are entering for the key field is valid and conforms to the expected format and constraints.
  
  
  Consult Documentation: Review the relevant SAP documentation or transaction help to understand the rules governing the key fields in the specific context you are working in.
  
  
  Use Transaction Codes: If you are using a specific transaction code, ensure that you are following the correct procedure for that transaction. Sometimes, using the wrong transaction can lead to unexpected errors.
  
  
  Check for Locks: Ensure that the record you are trying to modify is not locked by another user or process, which could prevent changes.
  
  
  Debugging: If you have access to debugging tools, you can analyze the program logic to see why the error is being triggered.
  
  
  Consult with SAP Support: If the issue persists and you cannot identify the cause, consider reaching out to SAP support or your internal SAP team for further assistance.
  
  
  Related Information:
  
  Key Fields: In SAP, key fields are defined in the data dictionary (SE11) and are crucial for the integrity of the database.
  Transaction Codes: Familiarize yourself with the transaction codes relevant to the task you are performing, as they may have specific requirements or limitations.
  SAP Notes: Check SAP Notes for any known issues or patches related to the error message AD420.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.