As of Dec 5th 2017, inventory_quantity and inventory_policy fields accessed through a json Liquid filter are deprecated. The json filter will not output those fields for shops created after Dec 5th. If you want to consume inventory information about a product, you can leverage variant.inventory_quantity and variant.inventory_policy. We recommend using that information behind a setting that the merchant has to turn on. This is a part of our efforts which kickstarted last year to eliminate bots and crawlers from knowing inventory levels of products from stores that they haven't explicitly been granted access to. Themes in the Shopify Theme Store will be updated before Dec 5th, 2017.
If you have any questions or concerns please comment in the thread below.
Yeah what is the alternative ? I even tried to just show the stock count as shown in https://help.shopify.com/en/themes/liquid/objects/variant#variant-inventory_quantity but no luck. I'm a noob !! Help me please !!! T.T