Strict Standards Error

I turned off debug and the errors went away

With debug off it is working, but how to fix with debug on?

If you go to Ce_Wp_Menu_Per_Page.php file you will see there is a class declared

class Ce_Wp_Menu_Per_Page {
   ...
}

and a constructor declared

function __construct() {
   ...
}

Just before that constructor you will see a function that has same name as class name.

function Ce_Wp_Menu_Per_Page() {
    self::__construct();
}

You need to remove this function or comment it.