Issue

ADB2C's login page is currently reading the URL parameter ui_locales.

This param is always passed in by PowerPages with the Site's Default Language setting value from the site management page when being redirected to the B2C.

This completely disables the ability to rely on the browser's language to show the good messages to the end user.

Idea

That would be great to have a checkbox just under the default language field like Do not pass the language to the B2C.

When this is checked, this would not pass the param anymore.

Current workaround

Use a custom B2C javascript to redirect the browser with the correct ui_locales param (actually depending on the browser's language) if the language does not match. Quite hackish but we are currently using that solution with our customers without too much complain.