How To Fix /AIF/MES321 - Non-existence check failed; selection from &1 returns a result

/AIF/MES321 - Overview

• Message type: E = Error

• Message class: /AIF/MES -

• Message number: 321

• Message text: Non-existence check failed; selection from &1 returns a result

Self-Explanatory Message

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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 /AIF/MES321 - Non-existence check failed; selection from &1 returns a result ?

  The SAP error message /AIF/MES321 Non-existence check failed; selection from &1 returns a result typically occurs in the context of the Application Interface Framework (AIF) when there is an issue with the data validation or existence checks during the processing of messages. This error indicates that a non-existence check, which is supposed to confirm that a certain record does not exist in the database, has failed because the selection query returned a result.
  
  Cause:
  
  Data Integrity Issues: The record that the system expected not to exist is actually present in the database. This could be due to incorrect data entry, duplicate records, or issues with data migration.
  Configuration Errors: The configuration settings for the AIF interface might be incorrect, leading to improper checks being performed.
  Business Logic Violations: The business rules defined in the AIF might be violated, causing the system to expect a non-existent record when it actually exists.
  Incorrect Mapping: If the mapping