Ticket #42238: 42238.patch

.php

@@ -46 +46 @@
                 $this->post_type = $post_type;
                 $this->namespace = 'wp/v2';
                 $obj = get_post_type_object( $post_type );
-                $this->rest_base = ! empty( $obj->rest_base ) ? $obj->rest_base : $obj->name;
-
+                if ($obj) {
+                        $this->rest_base = !empty($obj->rest_base) ? $obj->rest_base : $obj->name;
+                }
+                
                 $this->meta = new WP_REST_Post_Meta_Fields( $this->post_type );
         }