I was updating my add-on in order to obtain compatibility with all versions of Firefox. My add-on uses Javascript source code, calling a Java .jar library using Java.Packages object. I was able to obtain compatibility till to Firefox 15.0.1. In Firefox 16, however, support for LiveConnect seems to be removed. I've looked for a solution and I have found this message: https://bugzilla.mozilla.org/show_bug.cgi?id=748343 Despite I've tried some of the workarounds proposed at this link, I haven't got any result: JVM is not activated during the execution of the add-on Javascript source code. Error console does not provide any message. Can you provide a working example source code, showing how to call a Java public class contained in a .jar file from the Javascript source code of an add-on, in Firefox 16 or following ? Thanks in advance.