I18N not working when release

Hello guys

I followed the guide about i18n in Cocos Creator manual (installing extension, create en.js, zh.js…) and then it worked like a charm IN DEVELOPMENT MODE.

However, when I build the project for the Web Desktop platform, those localized labels only show the keys, not the values. I guessed that those file en.js, zh.js are not loaded into the window object.

Have anyone had a completely working example regarding i18n? Did I miss something regarding i18n?

(For now, I only need to internationalize the text of labels)

Thank you.