2046889 - SSL is deployed with a self-signed (test) certificate - client connects raise ssl_close() errors - SAP ASE

The Server's SSL certificate loaded without error and the listener port started:

Certificate load from file `$SYBASE/ase1503/ASE-15_0/certificates/ASTST.crt`: succeeded.
Trusted root certificates loaded from file '$SYBASE/ase1503/ASE-15_0/certificates/ASTST.txt': succeeded.
network name asetest, interface IPv4, address 10.123.456.78, type ssltcp, port 20070, filter ssl

Errors logged by the server.  one entry is logged per failed login attempt:

ssl_close(14): SSLClose(faf9da70) failed (-6989).
ssl_close(15): SSLClose(faf9e3b0) failed (-6989).
ssl_close(16): SSLClose(faf9ecf0) failed (-6989).
ssl_close(17): SSLClose(faf9f630) failed (-6989).

Error  returned to the client:

isql -Usa -P -I./local_interfaces
CT-LIBRARY error:
        ct_connect(): network packet layer: internal net library error: Net-Lib protocol driver call to connect two endpoints failed.

• SAP Adaptive Server Enterprise (ASE) 12.5.4
• SAP Adaptive Server Enterprise (ASE) 15.0.3
• SAP Adaptive Server Enterprise (ASE) 15.5
• SAP Adaptive Server Enterprise (ASE) 15.7

Security, SSL, Certificate , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , Problem