This SSL error occurs when the SSL/TLS client cannot verify the server's certificate due to the absence of the issuer's certificate in its trusted store. To resolve this, ensure the system time and date are accurate, update the trusted CA certificate bundle, explicitly specify the CA certificate if available, verify the certificate chain for completeness, and check for any network connectivity issues caused by firewalls or proxies. These steps will help address the SSL error "unable to get local issuer certificate" and enable successful establishment of secure connections.