Don't set venue related values without a venue

app/controllers/conferences_controller.rb

@@ -91,6 +91,7 @@ class ConferencesController < ApplicationController
               e.uid = conf.guid
               e.url = conference_url(conf.short_title)
               v = conf.venue
+              if v
                 e.geo = v.latitude, v.longitude if v.latitude && v.longitude
                 location = ''
                 location += "#{v.street}, " if v.street
@@ -100,6 +101,7 @@ class ConferencesController < ApplicationController
               end
             end
           end
+        end
         calendar.publish
         render inline: calendar.to_ical
       end

app/helpers/conference_helper.rb

@@ -36,6 +36,7 @@ module ConferenceHelper
         e.uid = proposal.guid
         e.url = conference_program_proposal_url(conference.short_title, proposal.id)
         v = conference.venue
+        if v
           e.geo = v.latitude, v.longitude if v.latitude && v.longitude
           location = ''
           location += "#{proposal.room.name} - " if proposal.room.name
@@ -43,6 +44,7 @@ module ConferenceHelper
           location += "#{v.postalcode} #{v.city}, " if v.postalcode && v.city
           location += "#{v.country_name}, " if v.country_name
           e.location = location
+        end
         e.categories = conference.title, "Difficulty: #{proposal.difficulty_level.title}", "Track: #{proposal.track.name}"
       end
     end