Django -- Can't get static CSS files to load

Read this carefully: https://docs.djangoproject.com/en/dev/ref/contrib/staticfiles/

Is django.contrib.staticfiles in your INSTALLED_APPS in settings.py?

Is DEBUG=False? If so, you need to call runserver with the --insecure parameter:

python manage.py runserver --insecure

collectstatic has no bearing on serving files via the development server. It is for collecting the static files in one location STATIC_ROOT for your web server to find them. In fact, running collectstatic with your STATIC_ROOT set to a path in STATICFILES_DIRS is a bad idea. You should double-check to make sure your CSS files even exist now.

For recent releases of Django, You have to configure static files in settings.py as,

STATIC_URL = '/static/' # the path in url

STATICFILES_DIRS = [
    os.path.join(BASE_DIR, "static"),
]

and use it with static template tag,

{% load static %}
<link rel="stylesheet" href="{% static 'css/bootstrap.css' %}">

Another simple thing to try is to stop, and then restart the server e.g.

$ python manage.py runserver

I looked into the other answers, but restarting the server worked for me.