How To Fix SAML2157 - Unknown user mapping mode: '&1'

SAP Error Message - Details

• Message type: E = Error

• Message class: SAML2 - SAML2 Nachrichten

• Message number: 157

• Message text: Unknown user mapping mode: '&1'

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 SAML2157 - Unknown user mapping mode: '&1' ?

  The SAP error message SAML2157, which states "Unknown user mapping mode: '&1'", typically occurs in the context of Single Sign-On (SSO) configurations using SAML (Security Assertion Markup Language). This error indicates that the system has encountered an unrecognized or invalid user mapping mode specified in the SAML configuration.
  Cause:
  The error can be caused by several factors:
  
  Incorrect Configuration: The user mapping mode specified in the SAML configuration is not recognized by the system. This could be due to a typo or an unsupported value.
  Version Mismatch: The SAML configuration might be using a feature or value that is not supported in the current version of the SAP system.
  Missing Parameters: Required parameters for user mapping may not be set, leading to the system being unable to interpret the mapping mode correctly.
  
  Solution:
  To resolve the SAML2157 error, you can take the following steps:
  
  
  Check Configuration:
  
  Go to the SAML configuration settings in your SAP system (usually found in transaction SAML2).
  Verify the user mapping mode specified. Ensure that it is one of the recognized values (e.g., USERID, EMAIL, etc.) and that there are no typos.
  
  
  
  Review Documentation:
  
  Consult the SAP documentation for the specific version you are using to ensure that the user mapping mode you are trying to use is supported.
  
  
  
  Update Configuration:
  
  If you find that the user mapping mode is incorrect, update it to a valid mode and save the configuration.
  
  
  
  Check for Updates:
  
  Ensure that your SAP system is up to date with the latest patches and updates, as newer versions may support additional user mapping modes.
  
  
  
  Test the Configuration:
  
  After making changes, test the SSO functionality to ensure that the error is resolved and that users can authenticate successfully.
  
  
  
  Consult SAP Support:
  
  If the issue persists after checking the configuration and documentation, consider reaching out to SAP support for further assistance.
  
  
  
  Related Information:
  
  SAML Configuration: Understanding how SAML works in SAP and the various configuration options available can help in troubleshooting issues.
  User Mapping Modes: Familiarize yourself with the different user mapping modes supported by your version of SAP, as this will help in configuring SSO correctly.
  SAP Notes: Check for any relevant SAP Notes that may address this specific error or provide additional guidance on SAML configurations.
  
  By following these steps, you should be able to identify and resolve the cause of the SAML2157 error in your SAP system.