Open file includes/class.format.phpLook for the function:display($text, $inline_images=true, $balance=true)And comment (or delete) this lines:$text = preg_replace_callback('/<img (*)(src="http+")(*)\/>/', function($match) { // Drop embedded classes -- they don't refer to ours $match = preg_replace('/class="*"/', '', $match); return sprintf('<span %s class="non-local-image" data-%s %s></span>', $match, $match, $match); }, $text);