This was working before and I was able to modify the menus as it's intended, but now every time I add any page or link to the menu and click save, its not saved. I tried creating a new menu and adding items there and that didn't work. I deactivated all the plugins, switched back to Twenty Eleven theme and that didn't work. Currently I overwrote all the wp-admin and wp-include folders and that didn't fix it.
The weird part is that I can rename the current items in the menu and it does save those changes or even if I remove and item from there it will work, but if I try to add a new one it doesn't get saved.