Treat deleted universes as gone universes

app/controllers/export_controller.rb

@@ -58,7 +58,8 @@ class ExportController < ApplicationController
           if value.is_a?(ActiveRecord::Associations::CollectionProxy)
             value = value.map(&:name).to_sentence
           elsif attr.end_with?('_id') && value.present?
-            value = Universe.find(value.to_i).name
+            universe = Universe.where(id: value.to_i).first
+            value = universe.name if universe
           end
 
           value