previene que se realicen consultas sin datos, trayendo demasiados datos

Form/ChoiceList/Loader/ClientChoiceLoader.php

@@ -93,7 +93,7 @@ class ClientChoiceLoader implements ChoiceLoaderInterface
     public function loadChoiceList($value = null)
     {
         $choices = array();
-        if (empty($this->selected)) {
+        if (is_array($this->selected) and !empty($this->selected)) {
             $choices = $this->getChoicesList(false);
 
             $missing_choices = array_flip($this->selected);