How To Fix SAML2166 - Can't decrypt string: '&1'

SAML2166 - Overview

• Message type: E = Error

• Message class: SAML2 - SAML2 Nachrichten

• Message number: 166

• Message text: Can't decrypt string: '&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.

Unfortunately, there isn't any extra information in this error notice.

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Smart SAP Assistant

• What is the cause and solution for SAP error message SAML2166 - Can't decrypt string: '&1' ?

  The SAP error message SAML2166, which states "Can't decrypt string: '&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 decrypt a SAML assertion or a related string, which is often due to issues with the encryption keys or certificates used in the SSO setup.
  Causes:
  
  Incorrect Encryption Keys: The keys used for encrypting the SAML assertions may not match the keys configured in the SAP system.
  Expired or Invalid Certificates: The certificates used for encryption may have expired or may not be valid.
  
  Configuration Issues: There may be misconfigurations in the SAML setup, such as incorrect endpoints or settings in the Identity Provider (IdP) or Service Provider (SP).
  Missing or Incorrect Trust Relationship: The trust relationship between the IdP and SP may not be properly established.
  Corrupted SAML Assertion: The SAML assertion being sent may be corrupted or malformed.
  
  Solutions:
  
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