I tried to add one menu to my existing site and after saving, menu is destroyed

After you had issues with WPML plugin and 2 months ago fixed your theme, I left my site as it was. Today, I wanted to add 1 single site to my main menu and after saving menu, many items at the end of my menu has gone.

This is how my menu looked before:

And you can see it how it looks now on live (again crippled) site

So far I have found out that my main menu is limited to 57 entries. Any other page I want to add to menu is not saved and after clicking “Menu save” button in WP, I get notice that my menu was updated, but instead newly added menu item is not added and also menu setting “Main menu” becomes unchecked.

I have contacted hosting and after setting all variable limits to maximum, they replied this issue has to do with theme’s coding:

I don’t know what to do, so please help as soon as possible. I also contacted you on your FB page but there was no reply from you yet. This is live site and very important menus are missing on my site. Site owner is running adwords campaigns so please do your best and review this issue as fast as possible. Thanks.