为什么显示网站目前无法处理此请求。尝试在linux服务器上传图像时出现HTTP ERROR 500

Question

我有一个关于codeigniter的项目，当我上传到cpanel并将文件上传到我的网站时，它现在在localhost上运行良好，它显示example.com目前无法处理此请求。 HTTP ERROR 500为什么？谁能告诉我该怎么做？

     public function doupload($id,$action)
   {

$config['upload_path']          = 'SliderImages/';
$config['allowed_types']        = 'gif|jpg|png|jpeg|psd|pdf|tiff';
$config['overwrite']            = TRUE;
$config['encrypt_name']         = false;
$config['max_size']             = 10000000;
$config['max_width']            = 999999;
$config['max_height']           =99999;

$this->upload->initialize($config);
$files = $_FILES;

if($action == "insert")
{


        if($_FILES['slide_image']['name'] !== '')
        {

                $_FILES['userfile']['name']= $files['slide_image']['name'];
                $file_name = $_FILES['userfile']['name'];
                $name =explode('.',$file_name);
                $_FILES['userfile']['name'] = $id. '.' .$name[1];
                $_FILES['userfile']['type']= $files['slide_image']['type'];
                $_FILES['userfile']['tmp_name']= $files['slide_image']['tmp_name'];
                $_FILES['userfile']['error']= $files['slide_image']['error'];
                $_FILES['userfile']['size']= $files['slide_image']['size']; 

                //$this->upload->do_upload();
                if (!$this->upload->do_upload())
                {                               
                    $error = array('error' => $this->upload->display_errors());         
                    return  $error; 
                    //print_r($error);die();
                }
                else
                {
                    $msg = array('upload_data' => $this->upload->data());               
                    return $this->upload->data('file_name');

                }

        }

  }


   }

当我检查服务器错误日志时显示

  [Sat Dec 17 03:52:20.696998 2016] [:error]
  [pid 32759:tid 140615796852480] [client 66.249.69.202:48854] 
  File does not exist: /home/mydomain/public_html/index.php

无法理解为什么会出现这个错误？

看到这张图片清楚地了解

[enter image description here][1]