When ever I try to add menu items past about 40 I get an error “The given object ID is not that of a menu item” and many of my menu items will disappear from the menu at random.
The site I am working on has approx 65 pages in total but I am unable to get them all in because of this.
I am referring to the new WordPress menu management interface
The solution I found was to get in touch with my webhost and have them up the PHP memory limit on my account from 64MB to 128MB. The problem went away after that.
Access your c-panel and site files then go to
wp-config.php
file and input the following line of codeWorked for me.