fix error

app/models/paper_criteria.rb

@@ -18,6 +18,7 @@ class PaperCriteria
   def epaper_topics
     tmp = EPaperTopic.where(:period.gte => self.start_date, :period.lte => self.end_date).can_display
     tmp = EPaperTopic.where(:period.gte => self.start_date, :period.lte => self.end_date).limit(1) if tmp.first.nil?
+    tmp
   end
 
   def other_emails_ids