Xulrunner runs but does nothing

Question

I am at my wits end. I've written a xul app and it runs fine if I open the .xul in firefox directly. But xulrunner doesn't cooperate at all. I can run my xul fine by using the -chrome flag for firefox and giving it an absolute path, but -app doesn't work on firefox either. I have all the files required (application.ini, chrome.manifest both in root and /chrome/ and tried with either missing as well) and their format has been checked and re-checked.

I was prepared to paste all my files here and link the code, but I've tried everything, including a boilerplate project from http://www.mozdev.org/projects/wizard/ (from the application wizard) which reacts the same way as my own project.

xulrunner returns no error message, nothing - it just stays there in the task manager, no cpu load, not loading anything to memory, inert.

I've tried other projects (https://github.com/matthewkastor/XULRunner-Examples - the periodic table works at least) but I can't get a single solid lead on why some projects run properly, while others just have xulrunner waiting and doing nothing. It also seems this is a rare problem because most people can at least run the boilerplate fine, even if their own projects don't initially run.

I don't think it's necessary to post my code at the moment since it behaves the same way as the boilerplate. Can anyone tell me possible reasons why xulrunner won't work with the boilerplate but will with the example project?

I'm running v25 on win xp sp2 and I have been searching and reading all day, so I'm pretty sure I've read everything related - thanks in advance; I hope 5 days of work won't be wasted :(

edit:

SOLUTION: I messed up and didn't notice that prefs.js was missing or empty. Even if you have no preferences in your app, prefs.js is needed to set up the environment and tell firefox or xulrunner where the xul file to start from is. Without this pointer it has no idea. Yes, the MDN article does state this and what it contains is accurate, this was a big mistake on my part, as it seems I subconsciously (or not?) ignored the prefs.js file because I had no need for preferences in my app. tl;dr if your apps don't work but the example files do, check your prefs.js even if you don't use preferences.

Answer 1

Posting this to close this question, since it doesn't need further answering.

The fault was with me - the app required a valid prefs.js file which I hadn't created because I was under the impression it wasn't required unless you intended to have preferences in your app. The MDN (at least at the time) specified this.