Hi, I’m experiencing the same problem BUT it’s only happening when I add the code featured here:
http://www.advancedcustomfields.com/resources/how-to/how-to-hide-acf-menu-from-clients/
into my CHILD THEME functions.php.
This problem does not occur when the code is placed in the parent theme’s functions.php
Could you let me know if you’re using a child theme?