Django 1.9.5, error using the admin: Uncaught TypeError: Cannot read property 'replace' of undefined

[murdav]

Dear Arthanson,

using Django 1.9.5 I got this error in the genericadmin.js file:

(function($) {
    var GenericAdmin = {
        url_array: null,
        fields: null,
        obj_url: "../obj-data/",
        admin_media_url: window.__admin_media_prefix__,

window.__admin_media_prefix__ is undefined.

Linked to django/django#4236

Thanks,

Davide