Theme app extension error when testing the app

Shopify Apps

Topic summary

Developers encounter an error when testing theme app extensions, receiving a message about enabling development store preview despite already having it enabled.

Solution Provided:

  • Turn OFF the developer preview option in the Partner Dashboard
  • Run build and deploy commands (npm run build and npm run deploy) to deploy all extensions
  • Access the Theme Editor in the store and manually add the theme extension as an App Block
  • Save the theme to display the extension UI

Status: Issue resolved. One user confirmed the workaround successfully fixed their problem, which appeared after switching to Remix.

Summarized with AI on November 17. AI used: claude-sonnet-4-5-20250929.
1

Hi everyone,

I’m developing a publish app, and trying to create a theme app extension to add my app to the theme editor. But I always face this issue when try run the app “To preview your extensions, make sure that development store preview is enabled in the Partner Dashboard”

I’ve already enabled the option.

developer_preview_enable.png
developer_preview_enable.png1072×234 9.2 KB

But it still doesn’t work.

Could you please advice?

Many thanks,

2

me too…

Please tell me solution

It was fine before using Remix.

3

You better turn it OFF.

Then run the below commands

npm run build
npm run deploy

This will deploy all the extensions attached to your project.

Now go to your Theme Editor of your store and add your theme extension app as an App Block and save the theme.

This will show your extension ui in the theme of your store.

4

thank you. solved!

5

Thats great to know.. KIndly mark it as accepted answer and like pls..