Nirvana Menu won't save order or deletions

I’ve deleted and recreated menus with various names and it won’t honor the menu item order.
Also when I delete a menu item, it remains. New menu items get placed last in order no matter where they were set. From the customize menu I get the following error message when I try to publish the menu: “Looks like something’s gone wrong. Wait a couple seconds, and then try again.” I don’t get an error message from the appearance/menus section, but it doesn’t save the changes either.

I’d prefer not to recreate the site to solve this problem.

Website: thebramblehouse.com