server output shows NoMethodError for created_at

NoMethodError

Started GET "/residents/1" for 127.0.0.1 at 2013-07-07 17:47:03 -0400
Processing by ResidentsController#show as HTML
  Parameters: {"authenticity_token"=>"TkgTe0hwIOCaHtU6UxXrh6QVOd4YDoK26svqX/lJVfk=", "id"=>"1"}
  Admin Load (0.4ms)  SELECT "admins".* FROM "admins" WHERE "admins"."id" = 1 LIMIT 1
  Resident Load (1.6ms)  SELECT "residents".* FROM "residents" 
  Resident Load (1.2ms)  SELECT "residents".* FROM "residents" WHERE "residents"."id" = ? LIMIT 1  [["id", "1"]]
  AssessmentPlanForm Load (1.0ms)  SELECT "assessment_plan_forms".* FROM "assessment_plan_forms" 
  AssessmentPlanForm Load (1.0ms)  SELECT "assessment_plan_forms".* FROM "assessment_plan_forms" WHERE "assessment_plan_forms"."resident_id" = 1 AND "assessment_plan_forms"."id" = ? LIMIT 1  [["id", "1"]]
  Rendered chart_alerts/up_to_date/_assessment_plan_form_success_alert.html.erb (0.1ms)
  MedRecordForm Load (9.7ms)  SELECT "med_record_forms".* FROM "med_record_forms" 
  EXPLAIN (5.5ms)  EXPLAIN QUERY PLAN SELECT "med_record_forms".* FROM "med_record_forms" 
EXPLAIN for: SELECT "med_record_forms".* FROM "med_record_forms" 
0|0|0|SCAN TABLE med_record_forms (~1000000 rows)

  MedRecordForm Load (8.8ms)  SELECT "med_record_forms".* FROM "med_record_forms" WHERE "med_record_forms"."resident_id" = 1 AND "med_record_forms"."id" = 1 LIMIT 1
  Rendered chart_alerts/up_to_date/_med_record_form_success_alert.html.erb (0.1ms)
  PersonalCareForm Load (3.2ms)  SELECT "personal_care_forms".* FROM "personal_care_forms" 
  EXPLAIN (1.4ms)  EXPLAIN QUERY PLAN SELECT "personal_care_forms".* FROM "personal_care_forms" 
EXPLAIN for: SELECT "personal_care_forms".* FROM "personal_care_forms" 
0|0|0|SCAN TABLE personal_care_forms (~1000000 rows)

  PersonalCareForm Load (3.1ms)  SELECT "personal_care_forms".* FROM "personal_care_forms" WHERE "personal_care_forms"."resident_id" = 1 AND "personal_care_forms"."id" = 1 LIMIT 1
  Rendered chart_alerts/up_to_date/_personal_care_form_success_alert.html.erb (0.1ms)
  WeightRecordForm Load (0.1ms)  SELECT "weight_record_forms".* FROM "weight_record_forms" 
  WeightRecordForm Load (0.2ms)  SELECT "weight_record_forms".* FROM "weight_record_forms" WHERE "weight_record_forms"."resident_id" = 1 AND "weight_record_forms"."id" = 1 LIMIT 1
  Rendered residents/show.html.erb within layouts/application (2930.4ms)
Completed 500 Internal Server Error in 2940ms

ActionView::Template::Error (undefined method `created_at' for nil:NilClass):
    62:   									<%= get_personal_care_form %>
    63: 									</div>
    64: 									<div class="span3" style="padding: 5px;">
    65: 										<%= get_weight_record_form %>
    66: 									</div>
    67: 								</div>
    68: 							</div>
  app/helpers/application_helper.rb:171:in `get_weight_record_form'
  app/views/residents/show.html.erb:65:in `_app_views_residents_show_html_erb__2992914799582651106_2202816500'