Administrator role gone

[synerdb]

When i create custom user role like Super-admin current Administrator privilege is gone as well as Administrator Role from drop-down is gone in new user creation section. Which throws error even while installing plugins which need Administrator privilege plugin does work at all.

[Martyr2]

Show us the code you are using to add the new custom role. I don’t think you can actually get rid of the role, but you can prevent it from being displayed in a drop down. Show us your hook/filter for adding the new role.

[synerdb]

add_role( 'mainadmin', 'Main-Admin', get_role( 'administrator' )->capabilities );
so if user role is not equal to mainadmin then denied access to menu,pages and so on:

add_action('admin_menu', function () {
	if(!current_user_can('mainadmin')) {
             remove_menu_page('plugins.php');
	         remove_menu_page('themes.php');
               so on......
         }
}