Javascript and css library could not be loaded in a custom page

Add-ons Development
1

I made an add-on which opens up a “first use” page right after it gets installed, in order for the user to set all the options. The problem is that in that page it doesn’t manage to load any css or js outside of the main ones (I’ve put the libraries in the “libs/js” and “libs/css” folders). They are loaded just fine on Chrome and they load on Firefox too if I install the add-on as an unpacked one, to debug it. They just don’t work in the published release.

The errors I get in the console are like this:
Loading failed for the <script> with source “moz-extension://<an id>/libs/js/jquery-3.3.1.min.js”.
(It says nothing about the css files but they aren’t loaded, either)

Do I have to reference the files with an absolute path, starting from the root? (starting with “/”)
Even though the add-on works correctly when installed as unpacked?

Thanks for any help.

2

Actually, nevermind. I noticed that I had referenced the libraries with “.min” in their name even though I was using the un-minified versions. I messed up an update when managing the development and release source codes.