Qui a osé écrire cet article ? Avez-vous vu cette insanité de votre code qui n'entraînera qu'un plantage de votre LocalSettings.php ???!!!
require_once "$IP/extensions/RSS/RSS.php"; // Et quand vous allez dans les sources, il n'EXISTE AUCUN RSS.php !!!
Bernard.jacob.liege@gmail.com
Sorry, I don't speak French. From what i understand, you seem to have the RSS folder with the extension not located in extenions/RSS/ (maybe in another subfolder? Be sure evertyhing is located in extenions/RSS/) Here is an exmaple of what you need to put into your LocalSettings.php to make this extension work in a wiki 1.27+:
#RSS Extension
wfLoadExtension( 'RSS' );
$wgRSSUrlWhitelist = array("https://somefeed1.com/somearticle.xml","https://gplusrss.com/rss/feed/12345",);
$wgRSSAllowLinkTag = true; //If you want to display images from the feed as well. large images won'te be downscaled so be aware.
$wgRSSItemMaxLength = 6000;
$wgRSSDateDefaultFormat = "d-m-Y H:i";
//if you are European and want to display your date like 28.06.2020
$wgRSSCacheAge = 10;
$wgAllowImageTag = true; //only needed if you want to display images