Metro C # Global Application Variables

I am building my first application for Windows 8 and I have a question. In Windows Phone 7, we can define all global variables in App.xaml.cs and access App.all_performers, for example, this works fine with default data types, but if I create a List of one object that I created as evento

public static List<evento> eventos_near = new List<evento>(); 

I have this error:

Inconsistent availability: the field type 'System.Collections.Generic.List <UrbaneousTry2.evento>' is less available than the field 'UrbaneousTry2.App.eventos_near'

Can anybody help me? I need lists and dictionaries for use on all pages of my application.