Setting DEBUG = False causes 500 Error

In my case, reading docs of third party apps properly saved me.

The culprit? django_compressor

I had

{% load compress %}
{% compress css %}
 ... css files linked here ..
{% endcompress %}

DEBUG = True always gave me 500. To fix it, I needed a line in my settings to get it running

COMPRESS_ENABLED = os.environ.get('COMPRESS_ENABLED', False)

I encountered the same issue just recently in Django 2.0. I was able to figure out the problem by setting DEBUG_PROPAGATE_EXCEPTIONS = True. See here: https://docs.djangoproject.com/en/2.0/ref/settings/#debug-propagate-exceptions

In my case, the error was ValueError: Missing staticfiles manifest entry for 'admin/css/base.css'. I fixed that by locally running python manage.py collectstatic.

Django 1.5 introduced the allowed hosts setting that is required for security reasons. A settings file created with Django 1.5 has this new section which you need to add:

# Hosts/domain names that are valid for this site; required if DEBUG is False
# See https://docs.djangoproject.com/en/1.9/ref/settings/#allowed-hosts
ALLOWED_HOSTS = []

Add your host here like ['www.beta800.net'] or ['*'] for a quick test, but don't use ['*'] for production.

I know this is late but I ended up here with a search for my error 500 with DEBUG=False, in my case it did turn out to be the ALLOWED_HOSTS but I was using os.environ.get('variable') to populate the hosts, I did not notice this until I enabled logging, you can log all errors to file with the below and it will log even when DEBUG=False:

# settings.py
LOGGING = {
    'version': 1,
    'disable_existing_loggers': False,
    'formatters': {
        'verbose': {
            'format' : "[%(asctime)s] %(levelname)s [%(name)s:%(lineno)s] %(message)s",
            'datefmt' : "%d/%b/%Y %H:%M:%S"
        },
        'simple': {
            'format': '%(levelname)s %(message)s'
        },
    },
    'handlers': {
        'file': {
            'level': 'DEBUG',
            'class': 'logging.FileHandler',
            'filename': 'mysite.log',
            'formatter': 'verbose'
        },
    },
    'loggers': {
        'django': {
            'handlers':['file'],
            'propagate': True,
            'level':'DEBUG',
        },
        'MYAPP': {
            'handlers': ['file'],
            'level': 'DEBUG',
        },
    }
}