Hey there, let's figure out why your design.css is throwing a 404 while JS and images load just fine. First, let's zero in on the key clue from your log:

[02/May/2018 09:41:21] "GET /static/css/design.css%25 HTTP/1.1" 404 1761

That %25 is URL-encoded for a plain % character—so your server is actually receiving a request for design.css% (with a trailing percent sign). That's why it can't find the file, since your actual CSS is named design.css without that extra %.

Here are the most likely fixes to check:

1. Fix the CSS Reference in Your Templates #

This is the most common culprit. Double-check how you're loading the CSS in your template files:

• Did you accidentally add an extra % when using the static template tag? For example, did you write {% static 'css/design.css%' %} instead of the correct {% static 'css/design.css' %}?
• Are you using string concatenation or variables to build the URL? Maybe a variable or template filter is appending an unwanted % to the path (like {{ css_path }}% where css_path already includes the filename).

Quick test: View the source code of your webpage, find the link tag for design.css, and check if the href attribute ends with %. If yes, that's exactly where the problem lives.

2. Verify Static File Collection & Paths #

Even though JS and images work, let's rule out static file setup issues:

• Head to your root static folder (the one generated by collectstatic) and confirm css/design.css exists there. If it's missing, re-run python manage.py collectstatic to make sure all static files are copied over correctly.
• Double-check your settings.py for the STATIC_ROOT configuration—it should point to that root static folder. For example:

  STATIC_ROOT = os.path.join(BASE_DIR, 'static')
  

• Ensure the file permissions for design.css are correct (it should be readable by your web server process).

3. Check for Unusual URL or Static File Configurations #

Since JS and images load, this is less likely, but worth a quick check:

• If you're running with DEBUG=False, make sure your web server (like Nginx or Apache) is configured to serve static files correctly from STATIC_ROOT. Again, since other static assets work, this is probably not the issue, but it's good to confirm.
• If you're using a custom static file storage backend, verify it's not modifying the file paths incorrectly (adding extra characters like %).

Quick Debug Step #

Try directly accessing http://your-domain/static/css/design.css (without the %25) in your browser. If the CSS loads fine, that confirms the problem is definitely in how the URL is being generated in your templates.

内容的提问来源于stack exchange，提问作者Alberto Sanmartin Martinez