Drupal 6 Feed Import Download of https://xml_feed_url failed with code 400
Use Drupal 6 Feeds Importer to import some data from a XML feed. Go to the xml feed url, can see the XML feed well there.
But when importing with Feeds Importer, got the error message
Download of https://xml_feed_url failed with code 400.
400 Bad Request: The request could not be understood by the server due to malformed syntax.
