--- a/wp/wp-admin/js/media-upload.js	Tue Jun 09 11:14:17 2015 +0000
+++ b/wp/wp-admin/js/media-upload.js	Mon Oct 14 17:39:30 2019 +0200
@@ -47,7 +47,7 @@
 			adminbar_height = parseInt( $('#wpadminbar').css('height'), 10 );
 		}
 
-		if ( tbWindow.size() ) {
+		if ( tbWindow.length ) {
 			tbWindow.width( W - 50 ).height( H - 45 - adminbar_height );
 			$('#TB_iframeContent').width( W - 50 ).height( H - 75 - adminbar_height );
 			tbWindow.css({'margin-left': '-' + parseInt( ( ( W - 50 ) / 2 ), 10 ) + 'px'});