In my opencart project my $product['href'] is
"index.php?route=product/product&path=60&product_id=81"
when i get to the page it only shows array() on the page.
if i then remove "&path=60" It shows the product..
you can edit link generation in product controller in path
/catalog/controller/product/product.php
search for
`'href' => $this->url->link
in default should be:
'href' => $this->url->link('product/product', 'product_id=' . $result['product_id']),
if it doesn't same as default so edit it.