Browser  : FF Nightly ( 52.0) OS: Ubuntu 14.0 I have created a test webextension to use connectNative to launch a native app on linux. However the native application is not getting launched , it reads the json correct and the 'path' correctly because if I change either the .json name or the path of the native app to something invalid .. it complains about it with appropriate error. When I try to debug the extension and set a break point at port = browser.runtime.connectNative("myapp")  ; the Step-In does not step into this call , rather it does the step over . I get a port object but the application does not start and there is no error message. Would appreciate if some can give pointers on : 1. What could possible make the application not start ( .. i did chmod 777 to shell script which in turn will launch will launch the application a java program , as well as to the java program). 2.Why step in is not working for me ? 3.How can this be debugged. Thanks