We detected an application built with production configuration. Angular DevTools only supports development build. about angular HOT 2 CLOSED

Check you console, if your application doesn't expose a ng global, then your app is not in developement mode.
Do you maybe have a enableProdMode() call in your app ?

from angular.

Thank you @JeanMeche.

In the main.ts, the enableProdMode() is called but there was an error in my if-statement. There I checked if the value of the .env-File is true. But it's a string and it always ran into true.

if (process.env['NX_PRODUCTION']) {
  enableProdMode();
}

So I changed the statement now and I explicitly check whether process.env['NX_PRODUCTION'] equals string 'true'

if (process.env['NX_PRODUCTION'] === 'true') {
  enableProdMode();
}

from angular.