handle errors and fix join form

config/application.rb

@@ -12,6 +12,8 @@ module Greenlight20
     # Application configuration should go into files in config/initializers
     # -- all .rb files in that directory are automatically loaded.
 
+    config.exceptions_app = self.routes
+
     config.loadbalanced_configuration = (ENV["USE_LOADBALANCED_CONFIGURATION"] == "true")
 
     # Setup BigBlueButton configuration.
@@ -33,4 +35,4 @@ module Greenlight20
     # Determine if GreenLight should allow non-omniauth signup/login.
     config.greenlight_accounts = (ENV['ALLOW_GREENLIGHT_ACCOUNTS'] == "true")
   end
-end
+end

config/environments/development.rb

@@ -9,8 +9,8 @@ Rails.application.configure do
   # Do not eager load code on boot.
   config.eager_load = false
 
-  # Show full error reports.
-  config.consider_all_requests_local = true
+  # Show custom error pages in development.
+  config.consider_all_requests_local = false
 
   # Enable/disable caching. By default caching is disabled.
   if Rails.root.join('tmp/caching-dev.txt').exist?

config/routes.rb

@@ -1,5 +1,10 @@
 Rails.application.routes.draw do
 
+  # Error routes.
+  match '/404', to: 'errors#not_found', via: :all
+  match '/422', to: 'errors#unprocessable', via: :all
+  match '/500', to: 'errors#internal_error', via: :all
+
   # Room resources.
   resources :rooms, only: [:create, :show, :destroy], param: :room_uid, path: '/r'