Fetch Data after route

i trying to fetch data after route file and folder. i check data come from database using module  and show all data in view page when i send data without routing.  but when i route then show me error
i route  page using this code. 

Code:

public function view_student($folder,$file)
        {
            
            $data['folder']=$folder;
            $data['page']=$file;
            $data['result']=$this->ci_mod->view_student();
            $this->load->view("deshboard",$data);
        }

page show using this formula but data not send from controller to view page. 
testing purpose i use this 
<?php
print_r($result);

?>
but show this error please see screenshot :  http://prntscr.com/9ed6jj

Without Routing show all data :    http://prntscr.com/9ed8sw

How i solved this problem ?