Inherit errors from StandardError instead of Exception.

app/logical/downloads/file.rb

@@ -3,7 +3,7 @@ require 'resolv'
 module Downloads
   class File
     include ActiveModel::Validations
-    class Error < Exception; end
+    class Error < StandardError; end
 
     RETRIABLE_ERRORS = [Errno::ECONNRESET, Errno::ETIMEDOUT, Errno::EIO, Errno::EHOSTUNREACH, Errno::ECONNREFUSED, Timeout::Error, IOError]
 

app/logical/pagination_extension.rb

@@ -1,5 +1,5 @@
 module PaginationExtension
-  class PaginationError < Exception; end
+  class PaginationError < StandardError; end
 
   attr_accessor :current_page, :records_per_page, :paginator_count, :paginator_mode
 

app/logical/pawoo_api_client.rb

@@ -6,7 +6,7 @@ class PawooApiClient
   STATUS1 = %r!\Ahttps?://pawoo\.net/web/statuses/(\d+)!
   STATUS2 = %r!\Ahttps?://pawoo\.net/@.+?/([^/]+)!
 
-  class MissingConfigurationError < Exception; end
+  class MissingConfigurationError < StandardError; end
 
   class Account
     attr_reader :json

app/logical/pixiv_api_client.rb

@@ -23,7 +23,7 @@ class PixivApiClient
     VistaPro Sculptris Comi\ Po! modo DAZ\ Studio 3D-Coat
   ]
 
-  class Error < Exception; end
+  class Error < StandardError; end
   class BadIDError < Error; end
 
   class WorkResponse

app/logical/post_sets/search_error.rb

@@ -1,4 +1,4 @@
 module PostSets
-  class SearchError < Exception
+  class SearchError < StandardError
   end
 end

app/logical/post_sets/wiki_page.rb

@@ -1,5 +1,5 @@
 module PostSets
-  class SearchError < Exception
+  class SearchError < StandardError
   end
 
   class WikiPage < PostSets::Post

app/logical/session_loader.rb

@@ -1,5 +1,5 @@
 class SessionLoader
-  class AuthenticationFailure < Exception; end
+  class AuthenticationFailure < StandardError; end
 
   attr_reader :session, :cookies, :request, :params
 

app/logical/upload_service/replacer.rb

@@ -1,7 +1,7 @@
 class UploadService
   class Replacer
     extend Memoist
-    class Error < Exception; end
+    class Error < StandardError; end
 
     attr_reader :post, :replacement
 

app/logical/user_deletion.rb

@@ -1,5 +1,5 @@
 class UserDeletion
-  class ValidationError < Exception; end
+  class ValidationError < StandardError; end
 
   attr_reader :user, :password