Script not included in umbraco-backoffice-extensions-js

Questions
1

I am trying to use a js library into a new dashboard. This is how I’m including the files:

{
 "javascript": [
      "/App_Plugins/uDashboard/webix/webix/codebase/webix.js",
      "/App_Plugins/uDashboard/webix/webix-angularjs.js",
      "/App_Plugins/uDashboard/js/dashboard.controller.js",
      "/App_Plugins/uDashboard/js/dashboard.services.js"
 ],
 "css": [ "/App_Plugins/uDashboard/webix/webix/codebase/webix.min.css"] 
}

The problem I have is that the script on the ‘webix-angularjs.js’ file complains because ‘webix’ is not defined. Webix is defined in the file before ‘webix.js’.

I can see that these files are concatenated by Umbraco in a custom file called ‘umbraco-backoffice-extensions-js.js’.

If I inspect that file, I can see that the content of webix.js is not there, but it includes the rest of my js: webix-angularjs.js, dashboard.controller.js and dashboard.services.js

If I type ‘webix’ on the Dev console I can in fact see that webix is not defined.

For some reason, the file is not being loaded by Umbraco.

EDIT

The content of webix-angularjs.js is here

The content of webix.js is here

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/106174-script-not-included-in-umbraco-backoffice-extensions-js
2

In the U13.1 version, the problem is still there. We have some problems with a custom plugin and with Contentment plugin.