FULL PRODUCT VERSION :
java -version
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) Client VM (build 25.121-b13, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Windows 10 Pro

EXTRA RELEVANT SYSTEM CONFIGURATION :
Firefox Version
50.1.0
Firefox Release
December 13, 2016

A DESCRIPTION OF THE PROBLEM :
Has anything changes within the deployJava.js script? From last night, my java applet has stopped loading in firefox in multiple locations.

Firefox has not updated since 15th December, the application and code has not changed for months, which leads me to believe it could be deployJava.js

On my page, i wrote console.log(deployJava) and in browserName2 it states, FirefoxNoPlugin

The page displays:
Java Plug-in is not supported by this browser. More info

I have uninstalled and reinstalled Java, no joy.

The strange thing is, if i goto the java.com website and click do i have Java, the applet
loads! However, im not sure if the official Java website uses the actual deployJava.js code.

In firefox, i have checked the plugins to make sure they are there and are active.


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------

var JAVA_MIN_VER = "1.5"
var APPLET_NAME = 'qz';
var APPLET_REF = 'Label Print';
var APPLET_URL = '<?php echo "$project_url/qz-print.1.8.0/"; ?>';
var APPLET_OURL = '<?php echo "$project_url/qz-print.1.8.0/jre6/"; ?>';
var APPLET_CLASS = 'qz.PrintApplet.class';

var attributes = {
                                    id: APPLET_NAME,
                                    code: APPLET_CLASS,
                                    codebase: APPLET_URL,
                                    archive: 'qz-print.jar',
                                    width: 0,
                                    height: 0
                                };
                                var parameters = {
                                    jnlp_href: 'qz-print_jnlp.jnlp',
                                    cache_option: 'plugin',
                                    cache_archive: 'qz-print.jar',
                                    cache_version: '0.1.8.0',
                                    cache_archive_ex: 'qz-print.jar;preload',
                                    disable_logging: 'false',
                                    initial_focus: 'false'
                                };

                                if (deployJava.versionCheck("1.7+") == true) {
                                    alert("OK");
                                }
                                else if (deployJava.versionCheck("1.6+") == true) {
                                    attributes['archive'] = 'qz-print.jar';
                                    attributes['codebase'] = APPLET_OURL;
                                    parameters['jnlp_href'] = 'qz-print_jnlp.jnlp';
                                }

                                deployJava.installJRE = function (requestVersion, ignore) {
                                    alert("Sorry, Java " + requestVersion + " does not appear to be installed");
                                }

                                console.log(deployJava);

                                deployJava.runApplet(attributes, parameters, JAVA_MIN_VER);
---------- END SOURCE ----------