diff --git a/app/controllers/test_controller.rb b/app/controllers/test_controller.rb
--- a/app/controllers/test_controller.rb
+++ b/app/controllers/test_controller.rb
@@ -19,7 +19,7 @@
 
     @submitted_test_request = TestRequest.new_from_form_params(@user,params[:test_request])
 
-    if @submitted_test_request.errors.length != 0
+    if ! @submitted_test_request.errors.empty?
       prepare_index_information
       render :action => 'index' and return
     end
diff --git a/config/initializers/cafe_grader_config.rb.SAMPLE b/config/initializers/cafe_grader_config.rb.SAMPLE
--- a/config/initializers/cafe_grader_config.rb.SAMPLE
+++ b/config/initializers/cafe_grader_config.rb.SAMPLE
@@ -5,12 +5,12 @@
 GRADER_ROOT_DIR = ''
 
 # These are where inputs and outputs of test requests are stored
-TEST_REQUEST_INPUT_FILE_DIR = Rails.root + '/data/test_request/input'
-TEST_REQUEST_OUTPUT_FILE_DIR = Rails.root + '/data/test_request/output'
+TEST_REQUEST_INPUT_FILE_DIR = (Rails.root + 'data/test_request/input').to_s
+TEST_REQUEST_OUTPUT_FILE_DIR = (Rails.root + 'data/test_request/output').to_s
 
 # To use ANALYSIS MODE, provide the testcases/testruns breakdown,
 # and the directory of the grading result (usually in judge's dir).
-TASK_GRADING_INFO_FILENAME = Rails.root + '/config/tasks.yml'
+TASK_GRADING_INFO_FILENAME = Rails.root + 'config/tasks.yml'
 
 # TODO: change this to where results are kept.
 GRADING_RESULT_DIR = 'RESULT-DIR'