Problems with Instance Variable in Controllenr

I've got problems with an instance variable in a controller.
the varible is initialized and has some entries which i give out in
second view(create). but in the third view (export) I become back this
...............ActionView::Template::Error (undefined method `length'
for nil:NilClass):
    1: <%=@month_issues.class%>
    2: <%=@month_issues.length%>
    3: <%@month_issues.each do |mi|%>
    4: <%= mi.text %>
    5: <%end%>
But in abrechnung_controller the vaiable is initialised as Array with
some antries, how it can be nil?


You realize instance variables are not carried forward from one action to another? They have to be set up on each request.