--- _wordpress-importer.php	2017-10-02 15:17:01.855565202 +0200
+++ wordpress-importer.php	2017-10-02 15:17:45.837565202 +0200
@@ -881,7 +881,7 @@
 		}
 
 		foreach ( $item['postmeta'] as $meta )
-			$$meta['key'] = $meta['value'];
+			${$meta['key']} = $meta['value'];
 
 		if ( 'taxonomy' == $_menu_item_type && isset( $this->processed_terms[intval($_menu_item_object_id)] ) ) {
 			$_menu_item_object_id = $this->processed_terms[intval($_menu_item_object_id)];