Call to undefined method mysqli_stmt::get_result

Please read the user notes for this method:

http://php.net/manual/en/mysqli-stmt.get-result.php

It requires the mysqlnd driver... if it isn't installed on your webspace you will have to work with BIND_RESULT & FETCH!

https://secure.php.net/manual/en/mysqli-stmt.bind-result.php

https://secure.php.net/manual/en/mysqli-stmt.fetch.php

So if the MySQL Native Driver (mysqlnd) driver is not available, and therefore using bind_result and fetch instead of get_result, the code becomes:

include 'conn.php';
$conn = new Connection();
$query = 'SELECT EmailVerified, Blocked FROM users WHERE Email = ? AND SLA = ? AND `Password` = ?';
$stmt = $conn->mysqli->prepare($query);
$stmt->bind_param('sss', $_POST['EmailID'], $_POST['SLA'], $_POST['Password']);
$stmt->execute();
$stmt->bind_result($EmailVerified, $Blocked);
while ($stmt->fetch())
{
   /* Use $EmailVerified and $Blocked */
}
$stmt->close();
$conn->mysqli->close();

Your system is missing the mysqlnd driver!

If you are able to install new packages on your (Debian/Ubuntu-based) server, install the driver:

sudo apt-get install php5-mysqlnd

and then restart your web server:

sudo /etc/init.d/apache2 restart