"App block not added" theme error
Updated 23 July 2026
The error: adding the date picker fails with "App block not added. Liquid templates don't support sections and blocks."
The cause: your theme is a vintage (Shopify 1.0) theme. Flare's picker is an app block, and app blocks require a Shopify 2.0 theme — this is a Shopify platform requirement, not a Flare setting.
Fix
- Get a 2.0 theme: every current Shopify Theme Store theme qualifies (Dawn is free), or update your existing theme if its developer ships a 2.0 version.
- Recreate your customisations on the new theme (Shopify's theme migration guide covers this), publish it.
- Reopen Flare and add the block again — it'll add cleanly.
Worth knowing
- 2.0 themes bring faster performance and drag-and-drop app blocks generally — the upgrade pays beyond Flare.
- If a rebuild isn't on the cards right now, talk to support about options — but the durable fix is the theme.