Run PHP script doesn’t work

Hi!
I’m trying to set up a fixed interval schedule to run a PHP script, but it doesn’t run.
The “Nest run”-time doesn’t update either.

I have the following setup
Run every 10 minutes
Action: Run PHP-script
Custom action: None
Argument (optional): None
PHP script path: URL to the php-file with the script

Here is the scrpt inside the PHP-file

<?php
//set the connection variables
$hostname = "";
$username = "";
$password = "";
$database = "";
$filename = "";

//connect to mysql database
$connection = mysqli_connect($hostname, $username, $password, $database) or die("Error " . mysqli_error($connection));

mysqli_query($connection, "TRUNCATE TABLE <code>Pristabell</code>");

// open the csv file
$fp = fopen($filename,"r");

//parse the csv file row by row
while(($row = fgetcsv($fp,"500",",")) != FALSE)
{
    //insert csv data into mysql table
    $sql = "INSERT INTO Pristabell (Produkt, Pris, Rabattkr, Rabattprosent, Lagerstatus, Butikk, TAGS) VALUES('" . implode("','",$row) . "')";
    if(!mysqli_query($connection, $sql))
    {
        die('Error : ' . mysqli_error($connection));
    }
}
fclose($fp);

//close the db connection
mysqli_close($connection);

?>