diff --git a/wp-includes/embed-template.php b/wp-includes/embed-template.php
index df2518f98f..fab8c84221 100644
--- a/wp-includes/embed-template.php
+++ b/wp-includes/embed-template.php
@@ -50,7 +50,7 @@ if ( have_posts() ) :
 			$image_size   = 'full'; // Fallback.
 
 			$meta = wp_get_attachment_metadata( $thumbnail_id );
-			if ( is_array( $meta ) ) {
+			if ( ! empty( $meta['sizes'] ) ) {
 				foreach ( $meta['sizes'] as $size => $data ) {
 					if ( $data['width'] / $data['height'] > $aspect_ratio ) {
 						$aspect_ratio = $data['width'] / $data['height'];
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 54d0ae66f9..977bab662e 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.5-alpha-36122';
+$wp_version = '4.5-alpha-36123';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.