I’ve stumbled across this problem too. It arises when I try to add an item to the admin nav.
It happens when I add the following code to my functions.php:
add_action('admin_menu', 'create_info_link');
function create_info_link() {
add_object_page(
'Info',
'Info',
'administrator',
'post.php?post=60&action=edit'
);
}