// Remove $display_multishop_toolbar and add instead $multishop_context to manage shop context per admin controller

controllers/admin/AdminStockInstantStateController.php

@@ -38,7 +38,6 @@ class AdminStockInstantStateControllerCore extends AdminController
 		$this->table = 'stock';
 		$this->className = 'Stock';
 		$this->lang = false;
-		$this->display_multishop_toolbar = false;
 
 		$this->fieldsDisplay = array(
 			'reference' => array(
@@ -103,6 +102,8 @@ class AdminStockInstantStateControllerCore extends AdminController
 		array_unshift($this->stock_instant_state_warehouses, array('id_warehouse' => -1, 'name' => $this->l('All Warehouses')));
 
 		parent::__construct();
+
+		$this->multishop_context = null;
 	}
 
 	/**