Categories, menus and product attributes disappeared

Hello there,

I have a wordpress multisite install with 2 sites on it which runs since 3 months now.

Today I my customer told me that, the products attributes (woocommerce) suddenly did not appear anymore. So I took a closer look and found the following problems:

#1
there is a notification that an automatic update could not be finished. From 3.9.2 to 4.0.1

#2
the post categories are not appearing in the backend anymore. but they still exist in the front end.

#3
menus are not displayed in the backend anymore but still exist in the front end. It only shows the field to creat new menus – when I do so – nothing is displayed. But in the database I can see that this menu is created

#4
the woocommerce project attributes are not showing up anymore. in the front end the lables of the attributes are still displayed but in the backend only 1 or 2 attributes are listed

Hope someone can help me!