How To Fix SLDAP_ICM013 - STARTTLS negotiation with directory service "&1" results in error &2&3&4

SAP Error Message - Details

• Message type: E = Error

• Message class: SLDAP_ICM - ICM LDAP Plugin: Messages

• Message number: 013

• Message text: STARTTLS negotiation with directory service "&1" results in error &2&3&4

What causes this issue?

The ICM LDAP plug-in has successfully established a connection to the
directory service, but the STARTTLS negotiation to promote the
connection from unencrypted to secure communication failed.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

With the help of the provided error information, the error eventually
can be solved. Typically, the server's certificate is not in the own
systems trust list.

Procedure for System Administrators

In the maintenance of LDAP Servers in the SAP system, the button
"Connection Test" can be used to validate the correctness of the current
connection data for a directory service. This button might reveal a
longer error message than available at other locations.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SLDAP_ICM013 - STARTTLS negotiation with directory service "&1" results in error &2&3&4 ?

  The SAP error message SLDAP_ICM013 indicates that there is an issue with the STARTTLS negotiation when trying to establish a secure connection with a directory service (like LDAP). This error typically arises when the SAP system is attempting to communicate with an LDAP server using the STARTTLS command, which is used to upgrade an unencrypted connection to a secure one.
  Causes:
  
  Incorrect LDAP Configuration: The LDAP server settings in the SAP system may be incorrect, including the server address, port, or security settings.
  TLS/SSL Certificate Issues: The SSL/TLS certificates used for the connection may be invalid, expired, or not trusted by the SAP system.
  Firewall or Network Issues: A firewall or network configuration may be blocking the connection or the STARTTLS command.
  LDAP Server Configuration: The LDAP server may not be configured to support STARTTLS or may have issues that prevent it from accepting secure connections.
  Version Mismatch: There may be a mismatch in the supported