App Bridge Modal content renders blank — <ui-modal> children not displayed

App Bridge
1

Modal opens (frame/overlay visible) but content area is completely empty. Even a minimal <Modal id="test"><p>hello</p></Modal> shows blank.

  • Store: sd32-jb-b.myshopify.com

  • 9 <ui-modal> elements confirmed present in app iframe DOM via DevTools

  • Same codebase works perfectly on a different dev store

  • Started ~Feb 9, 2026, no code changes on our end

  • All browsers affected (Chrome, Chrome incognito, Edge)

  • @shopify/app-bridge-react v4.1.10, @shopify/polaris v12.0.0

This appears related to the Feb 2 incident where CSS changes to the remote modals container broke modal rendering. That issue was marked as “mitigated” but may not be fully resolved for all stores.

2

Hi @den232

This seems to be specific to your app. The modal cannot load if you land directly to the app home /. It only works if you reload the page at /app/beads. Your app performs 302 redirect as soon as it lands on app home /. This is not a standard setup which could break when Shopify changes / tweaks how modal is loaded.

I think you have two options:

  • Option 1 (best): switch from ui-modal to use s-modal and s-app-window Modal
  • Option 2: continue using ui-modal but use 200 redirect on the client instead of 302 on the server