diff --git a/app/controllers/seminars_controller.rb b/app/controllers/seminars_controller.rb
index 6e07ed7..5d7165f 100644
--- a/app/controllers/seminars_controller.rb
+++ b/app/controllers/seminars_controller.rb
@@ -178,17 +178,21 @@ class SeminarsController < ApplicationController
     update_params = seminar_signup_contribute_params.merge('seminar_submission_values'=>params['seminar_submission_values'])
     flag = true
     update_params.permit!
-    if update_params['seminar_submission_values']['0']['value'].class==String
-      value = update_params['seminar_submission_values']['0']['value']
-      if !value.to_s.blank?
-        flag = false
-      end
-    else
-      update_params['seminar_submission_values']['0']['value'].each do |key,value|
-      if !value.to_s.blank?
+    if !update_params['seminar_submission_values'].nil?
+      if update_params['seminar_submission_values']['0']['value'].class==String
+        value = update_params['seminar_submission_values']['0']['value']
+        if !value.to_s.blank?
           flag = false
         end
+      else
+        update_params['seminar_submission_values']['0']['value'].each do |key,value|
+        if !value.to_s.blank?
+            flag = false
+          end
+        end
       end
+    else
+      flag = false
     end
     if flag
       update_params['seminar_submission_values']['0']['value']['en'] = ' '