Django Admin Login Issue with Signals

Based on the information you've provided, it appears you're experiencing an issue with the Django admin interface after implementing signals in your application. This is likely related to how your signals are being connected.

Possible Causes

The error you're experiencing might be related to one of these common issues:

1. Signal Connection Error: Based on the Django documentation, there's a specific error code (signals.E001) that occurs when a signal handler is connected to a signal with a lazy reference to a sender (app or model) that isn't properly installed or doesn't exist.

2. Login Cookie Issue: After successful authentication, Django might be failing to set the login cookie correctly, causing the admin page to redirect or show a 404.

Troubleshooting Steps

1. Check Your Signal Implementation

Review your signals.py and apps.py files. The most common issue is incorrectly referencing models in your signals:

PYTHONCopied
# Example of a problematic apps.py implementation
class YourAppConfig(AppConfig):
    name = 'your_app'
    
    def ready(self):
        import your_app.signals  # This might be causing the issue

Make sure:

• The models referenced in your signals exist
• The app is properly installed in INSTALLED_APPS
• You're not creating circular imports

2. Check for Session Cookie Issues

If the problem is related to session cookies:

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# Add this to your settings.py
SESSION_COOKIE_DOMAIN = 'localhost'  # Or your domain name

3. Verify User Permissions

Ensure your user account has both is_active and is_staff set to True. The admin site only allows access to users with both these fields enabled.

4. Debug Your Signals

Try temporarily commenting out parts of your signal implementation to identify which specific signal is causing the issue. You can gradually re-enable them to pinpoint the problematic code.

5. Check Server Logs

The terminal output you shared might contain more detailed error messages that could help identify the specific issue.

Next Steps

1. Share your signals.py and apps.py code for more specific guidance
2. Check if there are any errors in your Django console when the 404 occurs
3. Try running Django with the --traceback option to get more detailed error information

If you continue to experience issues, providing the specific implementation of your signals would help in diagnosing the exact problem.