wordpress stoped me to add links to the menu and also add widget to the widget areas

something wired happened to my wordpress site and I hope you can help me in figuring out what can cause the issue.

I am running the Multisite and some how when I add a widget to a sidebar or a widget area the widget does not show up and if I go back to the appearance/widget page the widget I added does not show as saved and I have the old set up of the widgets area. A similar problem is happening with the menu. I can not add new links to the menu. This problems started after I switch form a normal installation to a Multisite (to use Marketpress and is “Like eatsy” functionality).

Is it possible that I have limitations in place for adding menu items or widget for the site I added to the multisite?? I am sign in as superadministrator so that should not be an issue, or maybe I have set the site with some limitation and I have no idea on where to set does thing.

thanks for your help hope that you can help me in figuring out the problem and how to solve it.

thanks

Luca