The Build box block now warns you in the theme editor when its Box ID doesn't match a real box

If you sell build-a-box style bundles through Subi, the Build box block in your theme editor previously gave no signal when it was pointed at a box that no longer existed, or when your store had never set one up at all. The block would simply fail to show anything useful on the storefront, leaving you to notice only when a shopper reported a problem.

The theme editor now surfaces this directly: adding or editing a Build box block flags a clear warning when its Box ID doesn't match any of your store's active boxes, or when your store has no box configured yet, so you can fix it before publishing the page.

This is an editor-only warning. Shoppers browsing your storefront see no change; the fix is purely about catching a misconfiguration while you're setting up the block.