The bug is the Homepage / is broken when you combine the following:

• App Router
• Trailing slash
• i18n config
• Middleware

We have this configuration (and more) because in our production app :

• we have a domain per locale,
• we need trailing slash because of legacy,
• we need the middleware to get the locale in App Router because it does not work by default, also dealing with redirections, etc.

Actualy we have Pages Router + App Router because we did not have time to migrate all pages to App Router.

📝 Add dev domains in your /etc/hosts file:

127.0.0.1 www.dev.fr www.dev.es www.dev.it www.dev.de www.dev.ch www.dev.nl

• Go to: http://www.dev.fr
• See broken homepage (white screen) with logs:

  inject.bundle.js:1 Uncaught Error: Automatic publicPath is not supported in this browser
    at inject.bundle.js:1:12813
    at inject.bundle.js:1:12976
    at inject.bundle.js:1:271814
  (anonymous)	@	inject.bundle.js:1
  (anonymous)	@	inject.bundle.js:1
  (anonymous)	@	inject.bundle.js:1
  

You can test the following cases:

(revert any changes)

• Rename ./src/midleware.ts into ./src/__middleware.ts for instance
• Refresh http://www.dev.fr : the Home page is working.
• Go to http://www.dev.fr/test/ : the Test page is working also.

(revert any changes)

• Comment the trailinSlash: true line in next.config.ts.
• Refresh http://www.dev.fr : the Home page is working.
• Go to http://www.dev.fr/test/ : the Test page is working also.

(revert any changes)

• Comment the i18n config in next.config.ts.
• Refresh http://www.dev.fr : the Home page is working.
• Go to http://www.dev.fr/test/ : the Test page is working also.