CodeIgniter\Validation\Validation::setRules() must be of the type array, string given

processRules() function which inside System/Validation/validation.php 

I added this code and I fixed the problem. now validation work for  multiple variable  I sended like "name[]"

Code:

       if (is_array($value)) {
           foreach ($value as $k => $v) {
               $this->processRules($field, $label, $v, $rules, $data);
           }
           return true;
       }