Problem with menu

Hello, since a few days I’ve found some missing menu and sub-benu voices. I tried disabling all the categories and themes and reverting back to the original brand new installation and the plug in causing problem is the qtranslator-X.

Basically it removes some category voices from the menu and it won’t let me add new elements to the menu from the appearance admin panel. I’ve been working on a fix all day but nothing worked so far.
I had to change all the categories from the menu into custom links and now some of them are working and some are not.
I tried changing the plugin files to the older version when the problem wasn’t there but it still doesn’t work so I updated it to the latest version.

Here are some screenshots of the various phases of the error.

Menu from the admin panel with all the voices how they should be:
http://i.imgur.com/DEmXmsp.jpg
http://i.imgur.com/zJ11ztz.jpg
http://i.imgur.com/Hey255Q.jpg
http://i.imgur.com/EpRMnNT.jpg

This is what I saw after reinstalling the theme and switching off the plugins
http://i.imgur.com/2MBE2el.jpg

And this is what I saw after trying to add and modify voices from the menu
http://imgur.com/51B9wyb

After changing deactivating all the plug ins and the theme, I’ve changed all the voices of the menu from category to custom links and then reactivate the theme and the plug ins again. Then I tried to leave some of the voices into categories and this is what I see now.
http://i.imgur.com/kwH1RpC.jpg

As you can see from this close up from the admin panel ( http://i.imgur.com/ryoPS3C.jpg ) some of the voices are still missing.

This is the url of my website: http://www.gacktitalia.com

I really need the navigation to work fully or the site won’t be surfable by my viewers so it’s kind of urgent.
Waiting to hear from you.

https://wordpress.org/plugins/qtranslate-x/