1. The NW.js Version You're Using
It's the latest Chromium version 65 (v0.29.0)
2. Packaged assets, yes/no?
No, not for the tests, but in the end I would like them to remain hidden. The best would be to make some available for user to see, and some completely invisible.
3. Minimal "dummy" project reproducing the issue
I'm actually testing a solution I found in the forum (viewtopic.php?f=151&t=200764&p=1170491#p1170491)
But please find below a link to my c3p :
dropbox.com/s/m50yil3qihx1emq/dummynw.c3p
Thank you very much for your help.