How To Fix /UI5/APP_API126 - '&1' is mandatory

SAP Error Message - Details

• Message type: E = Error

• Message class: /UI5/APP_API -

• Message number: 126

• Message text: '&1' is mandatory

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 /UI5/APP_API126 - '&1' is mandatory ?

  The SAP error message /UI5/APP_API126 '&1' is mandatory typically indicates that a required field or parameter is missing in a request or operation related to SAP Fiori/UI5 applications. This error is often encountered when interacting with the SAP backend through OData services or when submitting forms in Fiori applications.
  Cause:
  
  Missing Mandatory Field: The error suggests that a mandatory field (denoted by &1) is not provided in the request. This could be due to user input errors or issues in the application logic.
  Incorrect Data Binding: If the UI5 application is not correctly binding data to the model, it may fail to send required fields to the backend.
  Backend Validation: The backend service may have validation rules that require certain fields to be populated before processing the request.
  
  Solution:
  
  Check Required Fields: Review the UI form or the request payload to ensure that all mandatory fields are filled out. The specific field that is mandatory will be indicated in the error message.
  Debugging: Use browser developer tools to inspect the network requests being sent to the backend. Look for the payload and verify that all required fields are included.
  Review Application Logic: If you are a developer, check the application code to ensure that all necessary data is being collected and sent to the backend. This may involve checking the data binding and model definitions.
  Backend Service Documentation: Consult the OData service documentation to understand which fields are mandatory and ensure that your application adheres to these requirements.
  Error Handling: Implement error handling in the application to provide user-friendly messages when mandatory fields are not filled out, guiding users to correct their input.
  
  Related Information:
  
  SAP Fiori/UI5 Documentation: Review the official SAP documentation for Fiori/UI5 applications to understand best practices for data binding and form handling.
  OData Service Metadata: Check the metadata of the OData service to identify which fields are marked as mandatory.
  SAP Community: Engage with the SAP Community forums for insights and solutions from other developers who may have encountered similar issues.
  
  By addressing the missing mandatory field and ensuring proper data handling in your application, you should be able to resolve the error message /UI5/APP_API126 '&1' is mandatory.