I am creating a menu consisting of various sections. When I add the 8th section which constists of :-
12/12 Header
12/12 Text/Shortcode
Several 6/6 Text/Shortcode Menu Items
If I add header and text/shortcode it will save correctly, once I had a 6/6 menu item the entire section disappears when I click update to save the work.
With this problem I cannot complete project for client which has already been delay due to other errors with theme.