handler404 returning Server Error (500) instead of 404.html - Django/Python

Using Django Mystery Errors
1

I spent several hours on this code and could not get to find out why I am getting server error (500) instead of 404.html in django program. Please see below codes and could someone help?

settings.py: 
DEBUG = False
ALLOWED_HOSTS = ['*']

urls.py: (app is mysite)
handler404 = "mysite.views.error_404"

views.py: 
def error_404(request, exception):
    return render(request, '404.html')
404.html:
{% extends "base.html" %}
{% load static %}
{% block main %}

some html text here

{% endblock %}

Please advise reason why I am not getting 404.html?

2

Start by looking at your console window where you’re running runserver. It should have the traceback showing where the problem is occurring.

3

Thank you KenWhitesell for reply, see attached message from the console. image

Django log is not generating traceback. Does attached photo mean much to you? Because I cannot figure out where problem is from.

4

Are you running this under Django’s runserver?

I see that you’ve got debug = False. That’s going to hide most of the useful information for debugging. Set debug = True and try this again.

5

Yes, i am running under django’ runserver.

I changed debug = True and then I got Page not found (404) error.

6

So how are we supposed to deal with that?

7

Handler404 is not supposed to return a normal HttpResponse, it needs to return an HttpResponseNotFound.

8

Try getting rid of all the extend commands from your 404 page and render a plain HTML page with no Django extends.

9

I got this problem this week and this site is one of the first results on google, i would like to answer the question here.
To solve this u need to change the nginx configuration to handle 404 erro.
In my case i had a 404.html page in /path/to/template and i added this lines to .conf file configuration insite server { } part
error_page 404 /404.html;
location = /404.html {
root /path/to/template ;
internal;
}

10

i get this error all the time its so annoying

11

I ran into this exact issue and solved it after some struggling…
I don’t know if it’s still relevant in 2025, but I’m sharing the trick in case it may help somebody.
The solution was to pass a default null value to ‘exception’ parameter (exception=None):

...
def error_404(request, exception=None):
    return render(request, '404.html')
...