I found my error .
It was the custom page properties, with « user » level declared , instead of admin or superadmin level.
If I set Require role with admin and superadmin to another custom page in the edit menu item , I can see it in the drop down list of « link to state » .
I have to study user properties .
now I can realize several pages .
But I know that i have a huge work to understand the behaviour of mango software and also angular.
Thanks for your help