How To Fix 5A421 - Only input 1 is allowed for unit "business event"

SAP Error Message - Details

• Message type: E = Error

• Message class: 5A - Basis Personnel Management

• Message number: 421

• Message text: Only input 1 is allowed for unit "business event"

What causes this issue?

You have entered "... units per xx business events" in the additional
data of relationship A022 ('requires'). You may only enter
"per 1 business event" when specifying the amount available per
business event.

How to fix this error?

Confirm this message. The number will be corrected to 1.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 5A421 - Only input 1 is allowed for unit "business event" ?

  The SAP error message 5A421 ("Only input 1 is allowed for unit 'business event'") typically occurs in the context of business event processing, particularly when dealing with input parameters that are expected to be singular but are provided in a different format.
  Cause:
  The error arises when the system expects a single input for a business event but receives multiple inputs or an incorrect format. This can happen in various scenarios, such as:
  
  Incorrect Input Format: The input provided does not match the expected format or type.
  Multiple Entries: The system is designed to handle only one business event at a time, but multiple events are being processed simultaneously.
  Configuration Issues: There may be a configuration issue in the business event setup that restricts the input to a single instance.
  
  Solution:
  To resolve the error, consider the following steps:
  
  
  Check Input Parameters: Ensure that you are providing only one input for the business event. Review the input data to confirm that it adheres to the expected format.
  
  
  Review Business Event Configuration: Check the configuration settings for the business event in the SAP system. Ensure that it is set up to accept the intended input correctly.
  
  
  Debugging: If you have access to debugging tools, you can trace the execution to see where the error is triggered. This may provide insights into what input is causing the issue.
  
  
  Consult Documentation: Refer to the SAP documentation or help files related to business events to understand the expected input and any constraints.
  
  
  Contact Support: If the issue persists, consider reaching out to SAP support or your internal IT team for assistance. They may have additional insights or solutions based on your specific system configuration.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide patches/updates.
  Transaction Codes: Familiarize yourself with transaction codes related to business events, such as those used for configuration or monitoring.
  User Forums: Engage with SAP community forums or user groups where similar issues may have been discussed.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.