システムをUbuntu10.04からUbuntu12.04にアップグレードしました。その過程で、redmineがアップグレードされました。10.04ではPPAppa：ondrej / redmineを使用し、12.04ではUbuntuストックバージョン（1.3.2 + dfsg1-1ubuntu1）を使用しています。
ほとんどの問題はまだ残っていますが、1つの特定の問題に問題があります。リストされておらず、直接アクセスすると（リンクをブックマークしました）、ログにエラーがスローされます。
Processing IssuesController#show (for AA.BB.CC.DD at 2012-10-19 11:19:24) [GET]
Parameters: {"action"=>"show", "controller"=>"issues", "id"=>"93"}
ActiveRecord::SubclassNotFound (The single-table inheritance mechanism failed to locate the subclass: 'WorkflowTransition'. This error is raised because the column 'type' is reserved for storing the class in case of inheritance. Please rename this column if you didn't intend it to be used for storing the inheritance class or overwrite Workflow.inheritance_column to use another column for that information.):
/usr/lib/ruby/vendor_ruby/active_record/base.rb:1671:in `instantiate'
/usr/lib/ruby/vendor_ruby/active_record/base.rb:665:in `find_by_sql'
/usr/lib/ruby/vendor_ruby/active_record/base.rb:665:in `collect!'
/usr/lib/ruby/vendor_ruby/active_record/base.rb:665:in `find_by_sql'
/usr/lib/ruby/vendor_ruby/active_record/base.rb:1582:in `find_every'
/usr/lib/ruby/vendor_ruby/active_record/base.rb:619:in `find'
/usr/lib/ruby/vendor_ruby/active_record/associations/association_collection.rb:60:in `find'
app/models/issue_status.rb:78:in `find_new_statuses_allowed_to'
/usr/lib/ruby/vendor_ruby/active_record/associations/association_proxy.rb:215:in `send'
/usr/lib/ruby/vendor_ruby/active_record/associations/association_proxy.rb:215:in `method_missing'
app/models/issue.rb:471:in `new_statuses_allowed_to'
app/controllers/issues_controller.rb:122:in `show'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:1333:in `send'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:1333:in `perform_action_without_filters'
/usr/lib/ruby/vendor_ruby/action_controller/filters.rb:617:in `call_filters'
/usr/lib/ruby/vendor_ruby/action_controller/filters.rb:610:in `perform_action_without_benchmark'
/usr/lib/ruby/vendor_ruby/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/usr/lib/ruby/vendor_ruby/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/usr/lib/ruby/vendor_ruby/action_controller/rescue.rb:160:in `perform_action_without_flash'
/usr/lib/ruby/vendor_ruby/action_controller/flash.rb:151:in `perform_action'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:532:in `send'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:532:in `process_without_filters'
/usr/lib/ruby/vendor_ruby/action_controller/filters.rb:606:in `process'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:391:in `process'
/usr/lib/ruby/vendor_ruby/action_controller/base.rb:386:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/routing/route_set.rb:438:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/dispatcher.rb:87:in `dispatch'
/usr/lib/ruby/vendor_ruby/action_controller/dispatcher.rb:121:in `_call'
/usr/lib/ruby/vendor_ruby/action_controller/dispatcher.rb:130:in `build_middleware_stack'
/usr/lib/ruby/vendor_ruby/active_record/query_cache.rb:29:in `call'
/usr/lib/ruby/vendor_ruby/active_record/query_cache.rb:29:in `call'
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
/usr/lib/ruby/vendor_ruby/active_record/query_cache.rb:9:in `cache'
/usr/lib/ruby/vendor_ruby/active_record/query_cache.rb:28:in `call'
/usr/lib/ruby/vendor_ruby/active_record/connection_adapters/abstract/connection_pool.rb:361:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/string_coercion.rb:25:in `call'
/usr/lib/ruby/vendor_ruby/rack/head.rb:9:in `call'
/usr/lib/ruby/vendor_ruby/rack/methodoverride.rb:24:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/params_parser.rb:15:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/session/cookie_store.rb:99:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/failsafe.rb:26:in `call'
/usr/lib/ruby/vendor_ruby/rack/lock.rb:15:in `call'
/usr/lib/ruby/vendor_ruby/action_controller/dispatcher.rb:106:in `call'
/usr/lib/ruby/vendor_ruby/rails/rack/static.rb:31:in `call'
/usr/lib/ruby/vendor_ruby/rack/urlmap.rb:52:in `call'
/usr/lib/ruby/vendor_ruby/rack/urlmap.rb:46:in `each'
/usr/lib/ruby/vendor_ruby/rack/urlmap.rb:46:in `call'
/usr/lib/ruby/vendor_ruby/rack/handler/webrick.rb:59:in `service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:104:in `service'
/usr/lib/ruby/1.8/webrick/httpserver.rb:65:in `run'
/usr/lib/ruby/1.8/webrick/server.rb:173:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:162:in `start_thread'
/usr/lib/ruby/1.8/webrick/server.rb:95:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `each'
/usr/lib/ruby/1.8/webrick/server.rb:92:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:23:in `start'
/usr/lib/ruby/1.8/webrick/server.rb:82:in `start'
/usr/lib/ruby/vendor_ruby/rack/handler/webrick.rb:13:in `run'
Rendering /usr/share/redmine/public/500.html (500 Internal Server Error)
この問題に関連する問題をredmineフォーラムで開きましたが、成功しませんでした（リンク）