symfony 2 : Namespace “Acme” does not contain any mapped entities

Question

I am following the book and on the page http://symfony.com/doc/current/book/doctrine.html

While following the book I am trying to work on relationship of product and cat

Answer 1

Check that the PHP opening and (optional) closing tags

and

?>

are correct in your file.

They are not included when you copy paste from the tutorial at http://symfony.com/doc/current/book/doctrine.html

I was stuck at the same problem. After looking at this post I started wondering why the syntax highlighting was broken and discovered that the opening and closing tags were missing. The error disappeared when the tags were included.