I'm using the pro version multi-protocol client, SecureFileTransferClient. When I upgraded to 4.5 from 4.2, FTPS_EXPLICIT stopped working.
Here is the debug log for the working 4.2 version:
https://www.dropbox.com/s/9s279xdjlwibmxm/edt4.2.txt
This is the debug log for the broken 4.5 version:
https://www.dropbox.com/s/bdu97sd3ubh5bwj/edt4.5.txt
Although this is not my exact code, here is essence of what I'm doing:
SecureFileTransferClient ftp = new SecureFileTransferClient();
ftp.setRemoteHost("an ip address");
ftp.setRemotePort(990);
ftp.setTimeout(30000);
ftp.setUserName("aUsername");
ftp.setPassword("theirPass");
ftp.getAdvancedFTPSettings().setConnectMode(FTPConnectMode.PASV);
ftp.setProtocol(Protocol.FTPS_EXPLICIT);
ftp.getAdvancedSSLSettings().setDisableSSLClosure(true);
ftp.connect();
ftp.setContentType(FTPTransferType.ASCII);
OutputStream out = ftp.uploadStream(cur,WriteMode.OVERWRITE);
//export(out);
out.flush();
try {out.close();} catch (Exception x) {}
try {ftp.disconnect();} catch (Exception x) {}