Attempting to use the Bulk Load Client to connect to Secure Cloud via HTTPS fails. The Bulk Load Client log shows SSL Handshake errors. The problem started happening on the evening of August 9, 2018.
Secure Cloud (US) was updated on August 9 to remove support for TLS 1.0 and TLS 1.1 protocols. The Bulk Load Client's imbulkloadclient.bat file by default points to the embedded JVM which is a Java 6 version (i.e. ..\_uninst\_jvm\bin\java) but Java 6 does not support TLS 1.2 protocol.
Install Java 8 and edit the Bulk Load Client's imbulkloadclient.bat file to instead use the Java 8 version of java.exe which support TLS 1.2 protocol.