php - Nested sets for Yii2 Invalid argument supplied for foreach() -

i using https://github.com/creocoder/yii2-nested-sets extension yii2!

so, first version yii1 in version have problem.

all done strictly according manual!

when created models earn error:

this error appear @ query category table. if delete behavior entire work ;(

categories model:

<?php  namespace backend\models;  use creocoder\nestedsets\nestedsetsbehavior; use yii\db\activerecord;  class categories extends activerecord {    public function behaviors() {     return [       'tree' => [         'class' => nestedsetsbehavior::classname(),          'treeattribute' => 'tree',       ],     ];   }    public function transactions()   {     return [       self::scenario_default => self::op_all,     ];   }    public static function find()   {     return new categoryquery(get_called_class());   } } 

categoryquery model:

<?php  namespace backend\models;  use creocoder\nestedsets\nestedsetsquerybehavior; use yii\db\activerecord;  class categoryquery extends activerecord {   public function behaviors() {     return [       nestedsetsquerybehavior::classname(),     ];   } } 

activequery instead activerecord in class categoryquery need