2996158 - SAML 2.0 authentication fails, user Source <email address> is longer than maximum length of a user name: 12 characters

• When performing a SAML 2.0 authentication, it fails and you are redirected to a logon screen or you will receive an authentication popup.
• SAML 2.0 secure diagnostic tool trace shows error like "User source <email address> is longer than maximum length of a user name: 12 characters".
• Below exception shows in SAML Security Diagnostic Tool trace which can be collected with the KBA 2960670.
  
  SAML20 SP (client <client number> ):  Exception raised:
  SAML20  SAML20 CX_SAML20_FEDERATION: User <email address> does not exist in client <client number>. Long text: User <email address> does not exist in client <client number>.
  SAML20     at CL_SAML20_FEDERATION->MAP_USERSOURCE_TO_USER_ID(Line 104)
  SAML20     at CL_SAML20_FEDERATION->CREATE_INSTANCE(Line 257)
  SAML20     at CL_SAML20_RESPONSE->VALIDATE_ASSERTION(Line 82)
  SAML20     at CL_SAML20_RESPONSE->VALIDATE(Line 64)
  SAML20     at CL_SAML20_SSO->VALIDATE_RESPONSE(Line 91)
  SAML20     at CL_HTTP_SAML20->PROCESS_LOGON(Line 345)
  SAML20     at CL_ICF_SAML_LOGIN->PROCESS_LOGON(Line 62)
  SAML20     at CL_HTTP_SERVER_NET->AUTHENTICATION(Line 2289)

SAML, SAML2, SAML20, SAML20 CX_SAML20_FEDERATION,is longer than maximum length of a user name: 12  characters, email, User id mapping mode , KBA , BC-SEC-LGN-SML , SAML 2.0 for ABAP , BC-SEC-LGN , Authentication , Problem