Hi,
I'm using a 3.0 project which I've converted to 3.1
When I want to use the template editor to add another link in 'menu.php'. It simply does not show up. See screenshots below.

(Adding another url called 'Superinvoerscript')

(For some reason, 'superinvoerscript' is nowhere to be seen).
This however only occurs with menu.php. When I use the template editor to change other pages (for example, adding an url on a '_list.php' page , everything works fine.
In 3.0, you could manually edit menu.php and add the url. In 3.1 however, it seems the structure of menu.php seems changed.