…would this have had any effect on the menu bar?
No.
–Update–
A little google search and this comes up… Your issue might be related to your server. This is an old post but might still be applicable to your setup.
http://stackoverflow.com/questions/12777433/wordpress-menu-items-not-being-saved
http://www.wpbeginner.com/wp-tutorials/how-to-fix-the-custom-menu-items-limit-in-wordpress/