Unhandled Error!

Trying to get property of non-object

Document	Product
Document type	CMS page
Line	8
Exception class	Cms_ExecutionException

Code Highlight

    <link rel="canonical" href="<?php echo $product->x_canonical; ?>" />
<?php else: ?>
    <link rel="canonical" href="https://<?php echo $_SERVER['HTTP_HOST']; ?><?php echo parse_url( $_SERVER['REQUEST_URI'], PHP_URL_PATH ); ?>" />
<?php endif; ?>
 
<meta name="description" content="<?php echo $this->page->description; ?>">
<meta name="keywords" content="<?php echo $this->page->title; ?>, <?= h($product->category_list[0]->name) ?>, <?php echo $this->page->keywords; ?>">
 
<? if( $product->x_bookpay == 99): ?>
    <title><?php echo $this->page->title; ?> for Sale | Mammoth Hire</title>
<? else: ?>
    <title><?php echo $this->page->title; ?> for Hire | Mammoth Hire</title>
<? endif ?>

#	Document	Type
1	Product	CMS page