Mysqli错误，谁能告诉我我的错误在哪里？

Question

谁能告诉我我的错误在哪里？

if (isset($_GET['acbid']) && !empty($_GET["acbid"])){
$agent_id=$_GET['acbid'];
echo $agent_id;
date_default_timezone_set('Asia/Hebron');
$month=date("m");
$day=date("d");
$year=date("y");                

if ($day>=26) {

$monthstt5= strtotime($year."-".$month."-"."26");
$finish_date5 = date("d-m-Y", strtotime("+1 month",$monthstt5));
 }else{
 $finish_date5 = date("d-m-Y", strtotime($year."-".$month."-"."26"));
 }



 $agent_id=$_GET['acbid'];
  $query ="select * from `bills` where `agent_id`=$agent_id ";

  $result = mysqli_query($conn,$query) or die(mysqli_error($conn));
   if (!$result) {
   echo "Could not successfully run query ($sql) from DB: " . mysql_error();
   exit;
  }else{while($row = mysqli_fetch_assoc($result)){
  $finish_date2=$row['finish_date'];
  $expire_time  = strtotime($finish_date2);
        $today = date("Y-m-d");
        $today_time = strtotime($today);
        echo mysqli_error($conn);

                  if ($expire_time <= $today_time){
                    echo "sadasdasd";
    if (($row['type']=='m') and ($row['status']=='on')) {
      $line_number=$row['line_number'];
      $total=$row['daily']+$row['monthly']+$row['sim'];
      $monthstt = strtotime($year."-".$month."-"."26");
      $finish_date3 = date("d-m-Y", strtotime("+1 month",$monthstt));
      $query=" UPDATE `bills` SET `total` = '$total', `start_date`='$finish_date2',`finish_date`='$finish_date5' WHERE `line_number` ='$line_number'and `agent_id` = '$agent_id'"; 
                  $result = mysqli_query($conn,$query) ;
                  echo mysqli_error($conn);
    }elseif (($row['type']=='d') and($row['status']=='on')) {
      $mon=$row['monthly'];
      $line_number=$row['line_number'];
      $total=$row['daily']+$row['sim']+$mon;
      $query=" select  * from line_pricing WHERE `line_number` ='$line_number'";

                  $result = mysqli_query($conn,$query) ;
                  echo mysqli_error($conn);

                  $monthly=$row['monthly'];
      $finaltotal=$total+$monthly;          

      $query=" UPDATE `bills` SET `type`='m',`monthly`= '$monthly',`total` = '$finaltotal', `start_date`='$finish_date2',`finish_date`='$finish_date5' WHERE `line_number` ='$line_number' and `agent_id` = '$agent_id' "; 
                  $result = mysqli_query($conn,$query) ;
                  echo mysqli_error($conn);
    }


    }

  }

}

}

错误是＆＃34;警告：mysqli_fetch_assoc（）要求参数1为mysqli_result，布尔值在第41行＆＃34; C / \ wamp64 \ www \ cellcom \ lines system \ administrative \ bills.php中给出;