Ticket #51251: 51251.1.patch

src/wp-admin/includes/ajax-actions.php

@@ -2625 +2625 @@
         wp_image_editor( $attachment_id, $msg );
         $html = ob_get_clean();
 
-        if ( $msg->error ) {
+        if ( isset( $msg->error ) ) {
                 wp_send_json_error(
                         array(
                                 'message' => $msg,