Php 显示网站当前无法处理此请求的原因。尝试在linux服务器中上载映像时出现HTTP错误500

我有一个关于codeigniter的项目，它现在在localhost上运行得很好，当我在cpanel中上传一个文件到我的站点时，它显示example.com目前无法处理这个请求。HTTP错误500为什么？谁能告诉我该怎么办

     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，它显示

  [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此错误

请看这张图片以便清楚地理解

[enter image description here][1]

---

请有人引导我，我被困了很长时间！您的index.php位于以下路径：/home/mydomain/public\u html/index.php？或者您是否在application/config的配置文件中修改了base_url？到处看看是的！基本url类似于“mydomain.com/”基本url应该是绝对的，包括协议：

$config['base\u url']=”http://somesite.com/somedir/“

或https