Hello @Aromorfia,

Welcome to the Klaviyo Community!

Instead of using the “Populate from Feed” option, do you see any products upon using the “Select from Catalog” option and filtering by the feed you wanted to use? 

From my experience, this can often times occur if the feed you are using contains no products because the feed was set up incorrectly. For example, if you have set up a Product Feed to only consist of products from a certain category or contains a certain tag, but you don’t actually have any products within those categories or tags. It would then be expected that no products would be captured by the Product Feed when selected for use in a product block.

I’ve also seen instances where some users may have more than one catalog syncing to Klaviyo from their integration where the designated catalog used to create/populate the feed actually contains no products. 

To alleviate many of these issues, I would suggest checking to make sure the catalog is syncing to Klaviyo correctly from your integration. You can also check to see what products are being synced to Klaviyo under the Catalog tab in your account. You can learn more about accessing and using the Catalog tab from the Guide to the Catalog Tab Help Center article.

I hope this helps!

David