How To Fix SAML2155 - Unknown user ID source: '&1'

SAP Error Message - Details

• Message type: E = Error

• Message class: SAML2 - SAML2 Nachrichten

• Message number: 155

• Message text: Unknown user ID source: '&1'

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 SAML2155 - Unknown user ID source: '&1' ?

  The SAP error message SAML2155, which states "Unknown user ID source: '&1'", typically occurs in the context of Single Sign-On (SSO) configurations using SAML (Security Assertion Markup Language). This error indicates that the system is unable to recognize the user ID source specified in the SAML assertion.
  Cause:
  
  Incorrect Configuration: The user ID source specified in the SAML assertion does not match any of the configured user ID sources in the SAP system.
  Missing User ID Source: The user ID source may not be defined in the SAP system's SAML configuration.
  Typographical Error: There may be a typo in the user ID source name in the SAML assertion or in the SAP configuration.
  Inconsistent Identity Provider (IdP) Settings: The IdP may be sending a user ID source that is not recognized by the SAP system.
  
  Solution:
  
  
  Check SAML Configuration:
  
  Go to the SAML configuration in the SAP system (transaction code SAML2).
  Verify that the user ID source specified in the SAML assertion matches one of the configured user ID sources in the SAP system.
  
  
  
  Update User ID Source:
  
  If the user ID source is not defined, you may need to add it to the SAML configuration.
  Ensure that the user ID source is correctly configured in the Identity Provider (IdP) settings.
  
  
  
  Review SAML Assertion:
  
  Use tools like SAML Tracer or browser developer tools to inspect the SAML assertion being sent from the IdP.
  Check for any discrepancies in the user ID source.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation for SAML configuration to ensure that all settings are correctly applied.
  
  
  
  Test with Different User:
  
  If possible, test the SSO with a different user to see if the issue is user-specific or a general configuration issue.
  
  
  
  Check Logs:
  
  Review the SAP system logs for any additional error messages or warnings that may provide more context about the issue.
  
  
  
  Related Information:
  
  SAML Configuration in SAP: Understanding how to configure SAML in SAP systems is crucial for troubleshooting SSO issues.
  Identity Provider Settings: Familiarize yourself with the settings in your IdP, as they play a significant role in the SSO process.
  SAP Notes: Check for any relevant SAP Notes that may address known issues or provide additional guidance on SAML configurations.
  
  If the issue persists after following these steps, consider reaching out to SAP support for further assistance.