Maybe I should go more into detail. The problem we had was that some charts and graphs in our application was not showing up only on Firefox ESR 38.3. Examination of the problem revealed that rickshaw was not loaded. The console had thrown an error from rickshaw.js saying that d3 was not loaded. But rickshaw.js was not available in debugger console !

The reason I did not raise a bugzilla was because the issue was intermittent ( ! ) and also I cannot share the whole application user interface with outsiders yet. Anyway, my working conjuncture is that these files are loaded from callbacks of AJAX requests and the problem happens when the callback for loading rickshaw fires before the callback for loading d3 has had a chance to fire. We ended up loading d3 manually as a workaround. But it is important to show rickshaw.js in the debugger since it enables us to set breakpoints there.