Index: src/wp-admin/load-scripts.php
===================================================================
--- src/wp-admin/load-scripts.php	(revision 38411)
+++ src/wp-admin/load-scripts.php	(working copy)
@@ -24,6 +24,7 @@
 if ( empty($load) )
 	exit;
 
+require( ABSPATH . 'wp-vendor/autoload_52.php' );
 require( ABSPATH . 'wp-admin/includes/noop.php' );
 require( ABSPATH . WPINC . '/script-loader.php' );
 require( ABSPATH . WPINC . '/version.php' );
Index: src/wp-admin/load-styles.php
===================================================================
--- src/wp-admin/load-styles.php	(revision 38411)
+++ src/wp-admin/load-styles.php	(working copy)
@@ -14,6 +14,7 @@
 
 define( 'WPINC', 'wp-includes' );
 
+require( ABSPATH . 'wp-vendor/autoload_52.php' );
 require( ABSPATH . 'wp-admin/includes/noop.php' );
 require( ABSPATH . WPINC . '/script-loader.php' );
 require( ABSPATH . WPINC . '/version.php' );