Shopify checkout UI extension target missing — or the placement is deprecated so the block never mounts.

Several checkout products can look like “the block is gone.” They do not share a settings panel. This page is only when a checkout UI extension’s declared target or checkout-editor placement is missing, renamed, or deprecated so the block never mounts on the surface you are staring at. The extension may install fine; the runtime may be healthy; the target string or slot is simply wrong or retired. Extension installed but never loads / blank runtime is shopify-checkout-ui-extension-not-loading. Settings → Checkout → Customize greyed out or permission-denied is shopify-checkout-editor-locked. Logo / colors / typography / CSS tokens not applying is shopify-checkout-branding-api-not-applying. Thank-you additional scripts / UI missing after payment is shopify-thank-you-page-customization-missing. Plus post-purchase one-click upsell page not loading is shopify-post-purchase-page-not-loading.

Six ordinary reasons the block never mounts: the target in shopify.extension.toml is a typo or retired string, the app still ships a deprecated placement Shopify removed, you placed a thank-you target on the information step (or the reverse), Partner Dashboard shows the extension against an old API version, Add app block does not list the extension under any live slot, or you are debugging a Functions customization / branding token and calling it a UI target.

Open the app’s extension config and copy the exact target (examples: purchase.checkout.block.render, purchase.checkout.actions.render-before, purchase.checkout.shipping-option-list.render-before, purchase.thank-you.block.render, order-status targets). Compare that string to Shopify’s current Checkout UI extension targets documentation — renamed and deprecated targets fail silently (no mount), which is the whole point of this page.

In Settings → Checkout → Customize on the published profile, open Add app block for the step you care about. Note whether the extension appears under that slot, under a different slot, or under none. If Customize itself will not open, stop and use checkout editor locked instead. If the target is valid, the block is in the picker, and the runtime still blanks, prefer checkout UI extension not loading.

Capture: app version / Partner release notes mentioning target renames, API version on the extension, which profile is published, which slot you expected, and a screenshot of Add app block with the extension missing or listed under the wrong surface. Soft-link branding when colors/logo are the only failure; soft-link thank-you / post-purchase when those surfaces are the intended product and the checkout information/shipping/payment step is fine.

Update the extension to a currently documented target. Remigrate deprecated targets — legacy checkout.liquid hooks and retired purchase.* strings do not mount on Checkout Extensibility. Bump the app on the shop; accept new scopes if Partner asks. Redeploy from Partner Dashboard if you own the extension.

On the published checkout profile, place the block in the editor slot that matches the target. A thank-you target will not appear on the information step; a shipping-option-list target will not mount on payment method. Publish the profile after placement — draft saves do not ship to buyers. Then open an incognito buyer checkout and confirm the block mounts on the intended step before pay (or on thank-you / order status if that is the target).

Soft notes after a clean target repair: not-loading if the target is valid but runtime/app install fails; editor locked if Customize is unavailable; branding API for logo/CSS tokens; thank-you customization and post-purchase for those surfaces when the checkout-step target is already correct.

Extension installed but never loads / blank runtime is shopify-checkout-ui-extension-not-loading. Customize greyed out / permission-denied is shopify-checkout-editor-locked. Branding API / editor branding not applying is shopify-checkout-branding-api-not-applying. Thank-you page customization missing is shopify-thank-you-page-customization-missing. Post-purchase page not loading is shopify-post-purchase-page-not-loading.

The only honest test for this page: documented current target string in the extension config, Add app block lists the extension under the matching slot on the published profile, profile published after placement, buyer checkout shows the block mounted on that surface. Anything else is a different product.

Stay DIY if you can spend one afternoon on the list above: compare the extension target to Shopify’s current list, update or remigrate deprecated targets, place the block on the matching live-profile slot, publish, and retest as a buyer. That is the whole playbook. No agency required. Short answers also live on the merchant FAQ. Related pages: extension not loading, editor locked, branding API, thank-you customization, post-purchase.

Pay for help when the work is not the target string — it is connecting the stack you already have so lead capture is not dying in DMs, storefront and checkout-ready exceptions land in a channel you already check, and the live store is one workflow instead of a spreadsheet plus a Slack bot you forgot. That is the Latch AI Ops install.

What $997 USD one-time buys: lead capture on the live store, ops alerts in a channel you already check, and a checkout-ready workflow. 72 hours after collaborator access, not after payment. One live Shopify store. Access plus a delivery thread. Store URL collected at checkout. Not a SaaS seat, not a theme rebuild retainer, not a conversion guarantee, not a brand or theme job.

Other shops’ public ranges, not testimonials: a checkout / ops install typically runs $500–$2,500. A full ops consulting block typically runs $2,000–$5,000. $997 is the cheap end of that work, sold as a 72-hour install of three systems — not as an earnings number or conversion-lift claim.

What it does not buy: more orders, recovered revenue, a forever checkout-extension uptime guarantee, or a case study. Latch AI Ops has not published customer proof because there are no customers yet. You are buying the install.

Checkout is on Whop. Operator is Nico. United States offer. You can revoke collaborator access after handoff. We do not take owner passwords.