How To Fix SAML2129 - Version mismatch

SAP Error Message - Details

• Message type: E = Error

• Message class: SAML2 - SAML2 Nachrichten

• Message number: 129

• Message text: Version mismatch

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 SAML2129 - Version mismatch ?

  The SAP error message SAML2129: Version mismatch typically occurs in the context of Single Sign-On (SSO) configurations using SAML (Security Assertion Markup Language). This error indicates that there is a mismatch between the SAML protocol versions being used by the Identity Provider (IdP) and the Service Provider (SP).
  Cause:
  
  Version Mismatch: The most common cause is that the IdP is configured to use a different version of SAML than what the SP is expecting. For example, if the IdP is using SAML 2.0 and the SP is configured for SAML 1.1, this error will occur.
  Configuration Issues: Incorrect or incomplete configuration settings in either the IdP or SP can lead to this error.
  Metadata Issues: If the metadata exchanged between the IdP and SP is outdated or incorrect, it may lead to version mismatches.
  Library or Framework Issues: If the libraries or frameworks used for SAML processing are outdated or incompatible, they may not support the required SAML version.
  
  Solution:
  
  Check SAML Versions: Ensure that both the IdP and SP are configured to use the same version of SAML. If one is using SAML 2.0, the other should also be configured for SAML 2.0.
  Update Configuration: Review and update the SSO configuration settings in both the IdP and SP. Make sure that the endpoints, bindings, and other settings are correctly configured.
  Update Metadata: Ensure that the metadata files exchanged between the IdP and SP are up to date. This includes checking for any changes in endpoints or supported SAML versions.
  Review Logs: Check the logs on both the IdP and SP for any additional error messages or warnings that may provide more context about the issue.
  Test with Different Tools: Use SAML testing tools to validate the SAML assertions and responses being sent between the IdP and SP. This can help identify where the mismatch is occurring.
  Consult Documentation: Refer to the documentation for both the IdP and SP for specific configuration guidelines related to SAML.
  
  Related Information:
  
  SAML Protocol Versions: Familiarize yourself with the differences between SAML 1.1 and SAML 2.0, as well as their respective features and capabilities.
  SAP Notes: Check SAP Notes and Knowledge Base Articles for any specific guidance or patches related to SAML configurations.
  Community Forums: Engage with SAP community forums or support channels for additional insights and shared experiences from other users who may have encountered similar issues.
  
  By following these steps, you should be able to resolve the SAML2129 error and ensure proper SSO functionality between your IdP and SP.