Shopify Online Store 2.0 JSON templates / section groups not loading or theme customizer blank.

Several products can look like “my theme editor is broken.” They do not share a settings panel. This page is only when Online Store → Themes → Customize opens blank / white, a JSON template never paints, or a section group (header / footer / aside) fails to load into the editor. Save or Publish that fails with a toast while the editor still renders is theme-editor-publish-failing. An App embeds toggle that never shows on the live storefront is app-embed-not-loading. AJAX cart / drawer that does not refresh after add-to-cart is cart-drawer-not-updating. Header dropdown that will not open on hover or tap is megamenu-not-opening. This page is only: JSON templates / section groups not loading or customizer blank.

Six ordinary reasons Customize blanks or a JSON layout will not load: invalid templates/*.json after a paste / Git merge, broken sections/header-group.json or footer-group.json, an unknown section type left behind after a theme update, a missing sections/*.liquid file the JSON still references, browser / ad-block / staff-role blockers that kill the admin editor shell, or you are debugging Save-Publish / app embed / cart drawer / megamenu instead. Walk them in that order. You already pay for Shopify Online Store. You do not need another seat to get Customize painting again.

Online Store → Themes → Customize on the Current theme. Note what you see: entire left rail + preview white, only the header / footer area empty while the page body loads, or one specific template (product, collection, index, page) white-screening when selected from the template picker. Open browser DevTools → Console on the admin tab. Screenshot any Theme Check / “Failed to load template” / JSON parse messages.

Honest proof: if the editor shell never paints or a named JSON template / section group fails to load, stay on this page. If the editor loads and Save / Publish shows a red toast, leave for theme-editor-publish-failing. If Customize looks fine and only a live storefront widget is wrong (cart drawer, megamenu, app embed), leave for that widget’s playbook. Do not mix those proofs.

Online Store 2.0 page layouts live as JSON under templates/. A trailing comma, an unclosed brace, a Liquid snippet pasted into a JSON file, or a bad merge conflict marker can make the customizer refuse to load that template — often as a blank preview rather than a friendly Save toast.

Fix: Themes → … → Edit code (or Shopify CLI). Open the template named in the error (for example templates/index.json, product.json, collection.json). Validate JSON. Remove conflict markers. Restore from the theme’s default template or a known-good backup if you are unsure. Save the file, reopen Customize, retest that template. Do not paste Liquid into a JSON template. A Save toast on an otherwise loaded editor is a different product — theme-editor-publish-failing.

OS 2.0 themes often wrap shared chrome in section groups — sections/header-group.json, footer-group.json, sometimes an aside / announcement group. If that group JSON is invalid, or it references a section file that no longer exists, Customize can load the page body while the header / footer pane stays empty — or the whole editor blanks when the group is required.

Fix: open the named *-group.json. Confirm every type maps to a real sections/*.liquid (or section JSON) in the theme. Restore the stock header / footer group from the theme author’s package if a merge deleted required sections. Save, hard-refresh Customize. A live megamenu that will not open while Customize itself looks fine is still megamenu-not-opening, not a section-group load failure.

Copying settings from Theme A into Theme B, pulling a Git branch, or upgrading a paid theme can leave JSON pointing at section types that do not exist in the destination theme. The customizer then fails to hydrate that template or group. App blocks left after an uninstall can show as unavailable types inside the JSON as well.

Fix: search the theme JSON for the unknown type string. Remove that section / block entry or replace it with a type that exists locally. Reinstall the app and remount the block only if you still want that feature. Retry Customize. If the editor loads and only a live App embed is missing on the storefront, leave for app-embed-not-loading.

Sometimes the JSON is fine and the admin shell is what fails: aggressive ad-block / privacy extensions killing Shopify admin scripts, an expired staff session, a staff account missing Themes permission, an outdated browser, or a second monitor / zoom quirk that hides the preview pane. That still presents as “customizer blank” to the operator.

Fix: try Incognito with extensions disabled, another browser, and an owner login. Confirm the staff role includes Themes. Hard refresh. If Customize loads cleanly for the owner and fails only for one staff user, fix permissions — do not rewrite JSON. If Customize is fine and Save still fails, that is again theme-editor-publish-failing.

Editor loads but Save / Publish fails or edits never go live is theme-editor-publish-failing. App embeds toggle missing on the live storefront is app-embed-not-loading. Cart / AJAX drawer not refreshing is cart-drawer-not-updating. Header megamenu / dropdown not opening is megamenu-not-opening.

The only honest test for this page: Customize opens blank / white, or a JSON template / section group fails to load into the editor. Validate and repair templates/*.json and section groups, remove unknown types, retry in a clean browser session. Anything else is a different product.

Stay DIY if you can spend one afternoon on the list above: prove blank vs one broken template / group, validate JSON, repair header-group / footer-group, remove unknown section types, rule out browser / staff blockers, and stop confusing theme-editor-publish-failing / app-embed / cart-drawer / megamenu with a blank customizer. That is the whole playbook. No agency required. Short answers also live on the merchant FAQ. Related pages: theme-editor-publish-failing, app-embed-not-loading, cart-drawer-not-updating, megamenu-not-opening.

Pay for help when the work is not the blank-customizer row — 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 blank-customizer 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.