One page not working since upgrading

I have two sites running “Latest Updates” pages. Since the recent update to 4.0 one of them is not displaying the information correctly and I can’t work out why. I am assuming some of the PHP may have been corrupted when upgrading.
The code is not identical between the pages so I can’t just copy and paste one across to the other.
I’ve been all over it looking for the problem but I have no knowledge of PHP but I have run the code through an online validator which has identified two depreciated functions. Unfortunately I have no idea what to replace them with.
The full code is below. If anyone can point me in the right direction it would be appreciated.

Example of the problem………..

This site displays OK https://www.fleetwood-trawlers.info/index.php/latest-updates/

This site doesn’t https://www.fleetwood-fishing-industry.co.uk/latest-updates/

……………………………………………………….

<?php

$num_per_page = 40;

$query = “select * from wp_posts where post_date < post_modified and post_content like ‘%Fleetwood Trawler -%’ and post_status like ‘%publish%’ order by post_modified DESC LIMIT ” . $num_per_page;

$result = mysql_query($query);

?>

<?php
while ($row = mysql_fetch_array($result)) {
echo ‘<pre style=”font-family:arial; margin:0; padding:0; height:18px !important”>’;
?>
• => – <?php echo date(‘jS \of F Y’,strtotime($row[“post_modified”])); ?>

<?php
echo ”;

}
?>