diff --git a/Gemfile b/Gemfile
index b7e6f710..8883213e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -29,7 +29,7 @@ gem "RedCloth"
 gem "sanitize", "~> 5.2"
 gem "will_paginate"
 gem "acts_as_list"
-gem "aasm", '~> 4.12.3'
+gem "aasm", '~> 5.1.1'
 gem "htmlentities"
 gem "rails_autolink"
 gem 'puma', '~> 4.3'
diff --git a/Gemfile.lock b/Gemfile.lock
index 60f3c4c1..1892e92c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,7 +9,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     RedCloth (4.3.2)
-    aasm (4.12.3)
+    aasm (5.1.1)
       concurrent-ruby (~> 1.0)
     actioncable (6.0.3.2)
       actionpack (= 6.0.3.2)
@@ -304,7 +304,7 @@ PLATFORMS
 
 DEPENDENCIES
   RedCloth
-  aasm (~> 4.12.3)
+  aasm (~> 5.1.1)
   actionpack-xml_parser (~> 2.0)
   activemodel-serializers-xml (~> 1.0.1)
   acts_as_list
diff --git a/app/controllers/preferences_controller.rb b/app/controllers/preferences_controller.rb
index 9e6db06d..b391ab9c 100644
--- a/app/controllers/preferences_controller.rb
+++ b/app/controllers/preferences_controller.rb
@@ -9,8 +9,8 @@ class PreferencesController < ApplicationController
   def update
     @prefs = current_user.prefs
     @user = current_user
-    user_updated = current_user.update_attributes(user_params)
-    prefs_updated = current_user.preference.update_attributes(prefs_params)
+    user_updated = current_user.update(user_params)
+    prefs_updated = current_user.preference.update(prefs_params)
     if (user_updated && prefs_updated)
       if params['user']['password'].present? # password updated?
         logout_user t('preferences.password_changed')
diff --git a/app/models/context.rb b/app/models/context.rb
index f9331fcb..2eaad6fb 100644
--- a/app/models/context.rb
+++ b/app/models/context.rb
@@ -35,7 +35,7 @@ class Context < ApplicationRecord
 
   validates_presence_of :name, :message => "context must have a name"
   validates_length_of :name, :maximum => 255, :message => "context name must be less than 256 characters"
-  validates_uniqueness_of :name, :message => "already exists", :scope => "user_id"
+  validates_uniqueness_of :name, :message => "already exists", :scope => "user_id", :case_sensitive => false
 
   def self.null_object
     NullContext.new
diff --git a/app/models/project.rb b/app/models/project.rb
index d10594a9..c7e62a85 100644
--- a/app/models/project.rb
+++ b/app/models/project.rb
@@ -18,7 +18,7 @@ class Project < ApplicationRecord
 
   validates_presence_of :name
   validates_length_of :name, :maximum => 255
-  validates_uniqueness_of :name, :scope => "user_id"
+  validates_uniqueness_of :name, :scope => "user_id", :case_sensitive => true
 
   acts_as_list :scope => 'user_id = #{user_id} AND state = \'#{state}\'', :top_of_list => 0
 
diff --git a/app/models/recurring_todo.rb b/app/models/recurring_todo.rb
index e9f09ff3..2c082fbf 100644
--- a/app/models/recurring_todo.rb
+++ b/app/models/recurring_todo.rb
@@ -12,8 +12,8 @@ class RecurringTodo < ApplicationRecord
 
   include AASM
   aasm :column => :state do
-    state :active, :initial => true, :before_enter => Proc.new { |t| t.occurrences_count = 0 }
-    state :completed, :before_enter => Proc.new { |t| t.completed_at = Time.zone.now }, :before_exit => Proc.new { |t| t.completed_at = nil }
+    state :active, :initial => true, :before_enter => Proc.new { self.occurrences_count = 0 }
+    state :completed, :before_enter => Proc.new { self.completed_at = Time.zone.now }, :before_exit => Proc.new { self.completed_at = nil }
 
     event :complete do
       transitions :to => :completed, :from => [:active]
diff --git a/app/models/todo.rb b/app/models/todo.rb
index c69bb69c..f40da3ca 100644
--- a/app/models/todo.rb
+++ b/app/models/todo.rb
@@ -70,13 +70,13 @@ class Todo < ApplicationRecord
 
   # state machine
   include AASM
-  aasm_initial_state = Proc.new { |t| (t.show_from && t.user && (t.show_from > t.user.date)) ? :deferred : :active}
+  aasm_initial_state = Proc.new { (self.show_from && self.user && (self.show_from > self.user.date)) ? :deferred : :active}
 
   aasm :column => :state do
 
     state :active
-    state :completed, :before_enter => Proc.new { |t| t.completed_at = Time.zone.now }, :before_exit => Proc.new { |t| t.completed_at = nil}
-    state :deferred,  :before_exit => Proc.new { |t| t[:show_from] = nil }
+    state :completed, :before_enter => Proc.new { self.completed_at = Time.zone.now }, :before_exit => Proc.new { self.completed_at = nil}
+    state :deferred,  :before_exit => Proc.new { self[:show_from] = nil }
     state :pending
 
     event :defer do
diff --git a/app/models/user.rb b/app/models/user.rb
index fd9bcaad..61c22e98 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -105,7 +105,7 @@ class User < ApplicationRecord
   validates_presence_of :password_confirmation, if: :password_required?
   validates_confirmation_of :password
   validates_length_of :login, within: 3..80
-  validates_uniqueness_of :login, on: :create
+  validates_uniqueness_of :login, on: :create, :case_sensitive => false
   validate :validate_auth_type
   validates :email, :allow_blank => true, format: { with: URI::MailTo::EMAIL_REGEXP }
 
diff --git a/app/views/contexts/show.html.erb b/app/views/contexts/show.html.erb
index 6b6460c7..f9e111ab 100644
--- a/app/views/contexts/show.html.erb
+++ b/app/views/contexts/show.html.erb
@@ -21,5 +21,5 @@
 
 <div id="input_box">
   <%= render :partial => "shared/add_new_item_form" %>
-  <%= render :file => "sidebar/sidebar" %>
+  <%= render :template => "sidebar/sidebar" %>
 </div>
diff --git a/app/views/feedlist/index.html.erb b/app/views/feedlist/index.html.erb
index 544282fe..3bf2318b 100644
--- a/app/views/feedlist/index.html.erb
+++ b/app/views/feedlist/index.html.erb
@@ -19,5 +19,5 @@
 </div>
 
 <div id="input_box">
-  <%= render :file => "sidebar/sidebar" %>
+  <%= render :template => "sidebar/sidebar" %>
 </div>
diff --git a/app/views/projects/show.html.erb b/app/views/projects/show.html.erb
index 0696e175..090371eb 100644
--- a/app/views/projects/show.html.erb
+++ b/app/views/projects/show.html.erb
@@ -42,5 +42,5 @@
 
 <div id="input_box">
   <%= render :partial => "shared/add_new_item_form" %>
-  <%= render :file => "sidebar/sidebar" %>
+  <%= render :template => "sidebar/sidebar" %>
 </div>
diff --git a/app/views/todos/index.html.erb b/app/views/todos/index.html.erb
index 11b85cca..54042a9c 100644
--- a/app/views/todos/index.html.erb
+++ b/app/views/todos/index.html.erb
@@ -12,5 +12,5 @@
 
 <div id="input_box">
   <%= render :partial => "shared/add_new_item_form" %>
-  <%= render :file => "sidebar/sidebar" %>
-</div>
\ No newline at end of file
+  <%= render :template => "sidebar/sidebar" %>
+</div>
diff --git a/app/views/todos/tag.html.erb b/app/views/todos/tag.html.erb
index 1c20c5fc..55a4120c 100644
--- a/app/views/todos/tag.html.erb
+++ b/app/views/todos/tag.html.erb
@@ -27,5 +27,5 @@
 
 <div id="input_box">
   <%= render :partial => "shared/add_new_item_form" %>
-  <%= render :file => "sidebar/sidebar" %>
+  <%= render :template => "sidebar/sidebar" %>
 </div>
diff --git a/test/controllers/contexts_controller_test.rb b/test/controllers/contexts_controller_test.rb
index 10adb746..f1660f95 100644
--- a/test/controllers/contexts_controller_test.rb
+++ b/test/controllers/contexts_controller_test.rb
@@ -10,7 +10,7 @@ class ContextsControllerTest < ActionController::TestCase
     login_as :admin_user
     get :index
   end
-  
+
   def test_show_sets_title
     login_as :admin_user
     get :show, params: { :id => "1" }
@@ -32,7 +32,7 @@ class ContextsControllerTest < ActionController::TestCase
     get :show, params: { :id => "1" }
     assert_template "contexts/show"
   end
-  
+
   def test_get_edit_form_using_xhr
     login_as(:admin_user)
     get :edit, xhr: true, params: { :id => contexts(:errand).id }
@@ -54,26 +54,25 @@ class ContextsControllerTest < ActionController::TestCase
   end
 
   # TXT feed
-  
   def test_text_feed_content
     login_as :admin_user
     get :index, params: { :format => "txt" }
-    assert_equal 'text/plain', @response.content_type
+    assert_equal 'text/plain', @response.media_type
     assert !(/&nbsp;/.match(@response.body))
   end
-  
+
   def test_text_feed_not_accessible_to_anonymous_user_without_token
     login_as nil
     get :index, params: { :format => "txt" }
     assert_response 401
   end
-  
+
   def test_text_feed_not_accessible_to_anonymous_user_with_invalid_token
     login_as nil
     get :index, params: { :format => "txt", :token => 'foo'  }
     assert_response 401
   end
-  
+
   def test_text_feed_accessible_to_anonymous_user_with_valid_token
     login_as nil
     get :index, params: { :format => "txt", :token => users(:admin_user).token }
@@ -81,35 +80,33 @@ class ContextsControllerTest < ActionController::TestCase
   end
 
   # REST xml
-  
   def test_show_xml_renders_context_to_xml
     login_as :admin_user
     get :show, params: { :id => "1", :format => 'xml' }
     assert_equal contexts(:agenda).to_xml( :except => :user_id ), @response.body
   end
-  
+
   def test_show_with_nil_context_returns_404
     login_as :admin_user
     get :show, params: { :id => "0" }
     assert_equal 'Context not found', @response.body
     assert_response 404
   end
-  
+
   def test_show_xml_with_nil_context_returns_404
     login_as :admin_user
     get :show, params: { :id => "0", :format => 'xml' }
     assert_response 404
     assert_select 'error', 'Context not found'
   end
-  
-  # RSS
 
+  # RSS
   def test_rss_feed_content
     login_as :admin_user
     get :index, params: { :format => "rss" }
-    assert_equal 'application/rss+xml', @response.content_type
+    assert_equal 'application/rss+xml', @response.media_type
     #puts @response.body
-  
+
     assert_select 'rss[version="2.0"]' do
       assert_select 'channel' do
         assert_select '>title', 'Tracks Contexts'
@@ -131,19 +128,19 @@ class ContextsControllerTest < ActionController::TestCase
       end
     end
   end
-  
+
   def test_rss_feed_not_accessible_to_anonymous_user_without_token
     login_as nil
     get :index, params: { :format => "rss" }
     assert_response 401
   end
-  
+
   def test_rss_feed_not_accessible_to_anonymous_user_with_invalid_token
     login_as nil
     get :index, params: { :format => "rss", :token => 'foo'  }
     assert_response 401
   end
-  
+
   def test_rss_feed_accessible_to_anonymous_user_with_valid_token
     login_as nil
     get :index, params: { :format => "rss", :token => users(:admin_user).token }
@@ -151,11 +148,10 @@ class ContextsControllerTest < ActionController::TestCase
   end
 
   # ATOM
-  
   def test_atom_feed_content
     login_as :admin_user
     get :index, params: { :format => "atom" }
-    assert_equal 'application/atom+xml', @response.content_type
+    assert_equal 'application/atom+xml', @response.media_type
     assert_equal 'http://www.w3.org/2005/Atom', html_document.children[0].namespace.href
     assert_select 'feed' do
       assert_select '>title', 'Tracks Contexts'
@@ -171,24 +167,22 @@ class ContextsControllerTest < ActionController::TestCase
       end
     end
   end
- 
+
   def test_atom_feed_not_accessible_to_anonymous_user_without_token
     login_as nil
     get :index, params: { :format => "atom" }
     assert_response 401
   end
-  
+
   def test_atom_feed_not_accessible_to_anonymous_user_with_invalid_token
     login_as nil
     get :index, params: { :format => "atom", :token => 'foo'  }
     assert_response 401
   end
-  
+
   def test_atom_feed_accessible_to_anonymous_user_with_valid_token
     login_as nil
     get :index, params: { :format => "atom", :token => users(:admin_user).token }
     assert_response :ok
   end
-
-  
 end
diff --git a/test/controllers/projects_controller_test.rb b/test/controllers/projects_controller_test.rb
index 023d82ba..4666dddd 100644
--- a/test/controllers/projects_controller_test.rb
+++ b/test/controllers/projects_controller_test.rb
@@ -82,7 +82,7 @@ class ProjectsControllerTest < ActionController::TestCase
   def test_rss_feed_content
     login_as(:admin_user)
     get :index, params: { :format => "rss" }
-    assert_equal 'application/rss+xml', @response.content_type
+    assert_equal 'application/rss+xml', @response.media_type
     #puts @response.body
 
     assert_select 'rss[version="2.0"]' do
@@ -128,7 +128,7 @@ class ProjectsControllerTest < ActionController::TestCase
   def test_atom_feed_content
     login_as :admin_user
     get :index, params: { :format => "atom" }
-    assert_equal 'application/atom+xml', @response.content_type
+    assert_equal 'application/atom+xml', @response.media_type
     assert_equal 'http://www.w3.org/2005/Atom', html_document.children[0].namespace.href
     assert_select 'feed' do
       assert_select '>title', 'Tracks Projects'
@@ -166,7 +166,7 @@ class ProjectsControllerTest < ActionController::TestCase
   def test_text_feed_content
     login_as :admin_user
     get :index, params: { :format => "txt" }
-    assert_equal 'text/plain', @response.content_type
+    assert_equal 'text/plain', @response.media_type
     assert !(/&nbsp;/.match(@response.body))
   end
 
@@ -238,7 +238,7 @@ class ProjectsControllerTest < ActionController::TestCase
   def test_xml_content
     login_as(:admin_user)
     get :index, params: { :format => "xml" }
-    assert_equal 'application/xml', @response.content_type
+    assert_equal 'application/xml', @response.media_type
 
     assert_select 'projects' do
       assert_select 'project', 3 do
diff --git a/test/controllers/todos_controller_test.rb b/test/controllers/todos_controller_test.rb
index 731b8497..70983854 100644
--- a/test/controllers/todos_controller_test.rb
+++ b/test/controllers/todos_controller_test.rb
@@ -128,17 +128,17 @@ class TodosControllerTest < ActionController::TestCase
 
     get :tag, params: { name: 'first.last.m' }
     assert_equal "text/html", request.format, "controller should set right content type"
-    assert_equal "text/html", @response.content_type
+    assert_equal "text/html", @response.media_type
     assert_equal "first.last", assigns['tag_name'], ".m should be chomped"
 
     get :tag, params: { name: 'first.last.txt' }
     assert_equal "text/plain", request.format, "controller should set right content type"
-    assert_equal "text/plain", @response.content_type
+    assert_equal "text/plain", @response.media_type
     assert_equal "first.last", assigns['tag_name'], ".txt should be chomped"
 
     get :tag, params: { name: 'first.last' }
     assert_equal "text/html", request.format, "controller should set right content type"
-    assert_equal "text/html", @response.content_type
+    assert_equal "text/html", @response.media_type
     assert_equal "first.last", assigns['tag_name'], ":name should be correct"
   end
 
@@ -479,7 +479,7 @@ class TodosControllerTest < ActionController::TestCase
   def test_rss_feed_not_completed
     login_as(:admin_user)
     get :index, params: { :format => "rss" }
-    assert_equal 'application/rss+xml', @response.content_type
+    assert_equal 'application/rss+xml', @response.media_type
     # puts @response.body
 
     assert_select 'rss[version="2.0"]' do
@@ -502,7 +502,7 @@ class TodosControllerTest < ActionController::TestCase
   def test_atom_feed_not_completed
     login_as :admin_user
     get :index, params: { :format => "atom" }
-    assert_equal 'application/atom+xml', @response.content_type
+    assert_equal 'application/atom+xml', @response.media_type
     assert_equal 'http://www.w3.org/2005/Atom', html_document.children[0].namespace.href
     assert_select 'feed' do
       assert_select '>title', 'Tracks Actions'
@@ -518,7 +518,7 @@ class TodosControllerTest < ActionController::TestCase
   def test_text_feed_not_completed
     login_as(:admin_user)
     get :index, params: { :format => "txt" }
-    assert_equal 'text/plain', @response.content_type
+    assert_equal 'text/plain', @response.media_type
     assert !(/&nbsp;/.match(@response.body))
     assert_number_of_items_in_text_feed 11
   end
@@ -526,7 +526,7 @@ class TodosControllerTest < ActionController::TestCase
   def test_ical_feed_not_completed
     login_as :admin_user
     get :index, params: { :format => "ics" }
-    assert_equal 'text/calendar', @response.content_type
+    assert_equal 'text/calendar', @response.media_type
     assert !(/&nbsp;/.match(@response.body))
     assert_number_of_items_in_ical_feed 11
   end
@@ -756,7 +756,7 @@ class TodosControllerTest < ActionController::TestCase
   def test_mobile_index_uses_text_html_content_type
     login_as(:admin_user)
     get :index, params: { :format => "m" }
-    assert_equal 'text/html', @response.content_type
+    assert_equal 'text/html', @response.media_type
   end
 
   def test_mobile_index_assigns_down_count
diff --git a/test/models/user_test.rb b/test/models/user_test.rb
index 66d5c801..607a0ff1 100644
--- a/test/models/user_test.rb
+++ b/test/models/user_test.rb
@@ -274,12 +274,12 @@ class UserTest < ActiveSupport::TestCase
   end
 
   def test_should_reset_password
-    users(:other_user).update_attributes(:password => 'new password', :password_confirmation => 'new password')
+    users(:other_user).update(:password => 'new password', :password_confirmation => 'new password')
     assert_equal users(:other_user), User.authenticate('jane', 'new password')
   end
 
   def test_should_not_rehash_password
-    users(:other_user).update_attributes(:login => 'jane2')
+    users(:other_user).update(:login => 'jane2')
     assert_equal users(:other_user), User.authenticate('jane2', 'sesame')
   end