[O] problem with org-babel-tangle

[Uwe Brauer]

Hello

I have the following minimal example

:tangle yes

#+BEGIN_SRC emacs-lisp
  (setq-default fill-column 79)
#+END_SRC


I put my cursor into the code block and execute C-c C-v t
and I obtain

Tangled 0 code blocks from new.org
C-c C-v f gives the same result.

What do I miss?

Thanks

Uwe Brauer