Well, i did a simple thing.
1. I made a custom menu going to Appearance > Menu
2. To make a menu without a link, I wrote the parent menu name in the "Custom Links" box in the "Label" textbox.
3.In the URL text box i wrote a dummy url (anything random).
4. Then i clicked the button "add to menu". So, this label was added to the menu.
5.Now in the menu area i clicked the dropdown button and then deleted the url textfield.
6. I finally clicked the button save menu.
And it worked for me. You can try it.