From:
<link itemprop="availability" href="http://schema.org/InStock" />{if $product.quantity <= 0}{if $product.allow_oosp}{if isset($product.available_later) && $product.available_later}{$product.available_later}{else}{l s='Out of stock'}{/if}{else}{l s='In stock'}{/if}{else}{if isset($product.available_now) && $product.available_now}{$product.available_now}{else}{l s='In Stock'}{/if}{/if}
Change to:
<link itemprop="availability" href="http://schema.org/InStock" />{if $product.quantity <= 0}{if $product.allow_oosp}{if isset($product.available_later) && $product.available_later}{$product.available_later}{else}{l s='Out of stock'}{/if}{else}{l s='Out of stock'}{/if}{else}{if isset($product.available_now) && $product.available_now}{$product.available_now}{else}{l s='In Stock'}{/if}{/if}
SOLVED