Issue on customize .ntp by scripting

Hi everyone,

I’m trying to load a .ntp project in python, customize some content and render it by scripting. But, some contents, like background videos and effects, is broken in render.

Rendering the project direct works well:

NatronRenderer project.ntp

Rendering with this script, the project render but the background is black in result.

# -*- Coding: UTF-8 -*-
# coding: utf-8

def createInstance(app, group):
  # This update and works fine
  title = app.getNode("Title")
  title.getParam("text").setValue("This is a test")
  # Render works fine, but the background image is black
  writer = app.getNode("MyWriter")
  app.render(writer, 0, 100)

I am doing something wrong?
What is the best option to customize it with scripting?

I solved the problem reloading all images of the project, one by one.
For exemple, backtround:


Maybe it is a bug, but for now, it works.