Why do some requests return a 404 error?

Why do some requests return a 404 error?

If, during the test, you get 404 errors on images or JavaScript or CSS files, it indicates that the files are referenced and used in the HTML page, but are missing on the server.

The final user usually does not notice that these files are missing because the browser ignores this type of error. Either make corrections to the application (add the missing files or delete the reference to them in the web page), delete the request from the Virtual User or set the option to smart-ignore 404 error codes. For more information, see Error handling.