symfony 2 No route found for “GET /”

Question

Symfony2 returns No route found for \"GET /\" when I try to run http://localhost/app_dev.php, but this url works: http://localhost/app_dev.php/hello/Symfony. I removed AcmeD

Answer 1

The above answers are wrong, respectively aren't answering why you're having troubles viewing the demo-content prod-mode.

Here's the correct answer: clear your "prod"-cache:

php app/console cache:clear --env prod