Header Menu (Navigation) 'floats' when trying to add a link


I have begun to get this error after the upfront theme update.

Whenever I try to add a link to my navigation menu, the menu 'floats' and makes it impossible for me to designate the linkage. I have tested in chrome/IE and I am seeing the same problem.

Additionally, the menu navigation appears to be buggy overall – adding additional drop-down menus, etc.

Please take a look.