Se agrega chequeo para determinar si es un array lo que retorna desde el webservice

src/FTTHBundle/Controller/ONUCRUDController.php

@@ -45,7 +45,7 @@ class ONUCRUDController extends CRUDController
             $webservice = $this->get("webservice");
             $filters = array("qb-ids" => implode(",",$clientsIds), 'qb-criteria' => true);
             $clients = $webservice->getData($clientApi, $filters);
-            if($clients)
+            if(is_array($clients) && !empty($clients))
                 foreach($clients as $client) {
                     $_clients[$client['id']] = "{$client['id']} - {$client['name']}";
                 }