diff --git a/app/views/email/signup_email.html.erb b/app/views/email/signup_email.html.erb
index a595543..9a0583d 100644
--- a/app/views/email/signup_email.html.erb
+++ b/app/views/email/signup_email.html.erb
@@ -6,4 +6,4 @@
 <% else %>
 	<%= t('seminar.email_signup_content') %>
 <% end %>
-<%= (@data['extra_text'] rescue "").html_safe %>
\ No newline at end of file
+<%= (@data['extra_text'] rescue "").to_s.html_safe %>
\ No newline at end of file
diff --git a/app/views/email/submission_email.html.erb b/app/views/email/submission_email.html.erb
index d2b1665..a0f31c2 100644
--- a/app/views/email/submission_email.html.erb
+++ b/app/views/email/submission_email.html.erb
@@ -6,4 +6,4 @@
 <% else %>
 	<%= t('seminar.email_submission_content') %>
 <% end %>
-<%= (@data['extra_text'] rescue "").html_safe %>
\ No newline at end of file
+<%= (@data['extra_text'] rescue "").to_s.html_safe %>
\ No newline at end of file
diff --git a/app/views/seminars/index.html.erb b/app/views/seminars/index.html.erb
index eba6e34..2c6071b 100644
--- a/app/views/seminars/index.html.erb
+++ b/app/views/seminars/index.html.erb
@@ -5,7 +5,7 @@
 	@total_pages = data["total_pages"]
 	@time_now = data["time_now"]
 %>
-
+<% begin %>
 <table class="table table-hover table-striped seminar-index">
 	<caption>
 		<h3><%= t('seminar.seminar') %></h3>
@@ -23,11 +23,11 @@
 		<% 
 			@seminars.each do |seminar| 	
 
-			  if !seminar.registration_status.blank? and seminar.signup_start_date <= @time_now and ( seminar.signup_end_date.nil? or  seminar.signup_end_date+1 >= @time_now )
+			  if !seminar.registration_status.blank? and (seminar.signup_start_date <= @time_now rescue false) and ( seminar.signup_end_date.nil? or  seminar.signup_end_date+1 >= @time_now )
 			  	sign_up = ('<a href="'+ OrbitHelper.url_to_show(seminar.to_param) + '" target="_blank">' + t('seminar.signup') + '</a>').html_safe
 			  elsif seminar.registration_status.blank?
 			  	sign_up = t('seminar.sign_up_not_open')
-			  elsif seminar.signup_start_date > @time_now
+			  elsif (seminar.signup_start_date > @time_now rescue false)
 			  	sign_up = t('seminar.sign_up_not_yet')
 			  else
 			  	sign_up = t('seminar.sign_up_overdue')
@@ -42,7 +42,7 @@
 				<%= sign_up %> <br />
 
 				<%= 
-				if !seminar.registration_status.blank? and seminar.registration_status.include?('C') and seminar.contribute_start_date <= @time_now and ( seminar.contribute_end_date.nil? or seminar.contribute_end_date+1 >= @time_now )
+				if !seminar.registration_status.blank? and seminar.registration_status.include?('C') and (seminar.contribute_start_date <= @time_now rescue false) and ( seminar.contribute_end_date.nil? or (seminar.contribute_end_date+1 >= @time_now rescue false) )
 					if !session[:seminar_signup_id].blank? 
 						if session[:seminar_main_id] == seminar.id
 						('<a href="'+ OrbitHelper.url_to_show(seminar.to_param) + '?method=con_upload">' + t('seminar_signup.uploads') + '</a>').html_safe
@@ -59,5 +59,8 @@
 		<% end %>
 	</tbody>
 </table>
-
+<% rescue => e
+puts [e,e.backtrace]
+	end
+%>
 <%= create_pagination(@total_pages).html_safe if @total_pages > 1 %>
\ No newline at end of file
diff --git a/app/views/seminars/show.html.erb b/app/views/seminars/show.html.erb
index 2d5a83c..ef3d8bd 100644
--- a/app/views/seminars/show.html.erb
+++ b/app/views/seminars/show.html.erb
@@ -212,7 +212,7 @@
 
       <div class="form-group">
         <div class="col-sm-offset-2 col-sm-10">
-          <input type="hidden" name="referer_url" value="<%= request.original_url.split(request.env["HTTP_HOST"]).last %>">
+          <input type="hidden" name="referer_url" value="<%= request.original_url.split(request.env["HTTP_HOST"]).last rescue "/" %>">
           <input type="hidden" name="seminar_signup[seminar_main_id]" value="<%= @seminar.id %>">
           <%= f.submit "Submit", class: 'btn btn-primary', :id => 'button-mail' %>
           <%= f.button "Delete", type: 'reset', class: 'btn' %>