# Problems upgrading from 2.2.2 to 2.3.2 - uninitialized constant ActionController::Failsafe (NameErr **URL:** \ **Category:** Rails\ **Created:** [April 19, 2009, 11:53am UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899 "2009-04-19T11:53:16Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![dkam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/e5b9ba/32.png) [@dkam](https://www.ruby-forum.com/u/dkam)\ **Post date:** [April 19, 2009, 11:53am UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899/1 "2009-04-19T11:53:16Z")
Hi Guys, I’m trying to get my app up to rails 2.3.2, but I have a problem - I can’t start the app with Mongrel or Thin, and the “rake middleware” all return the same error. I’m using the edge version of rails so my normal dev environment can stay at 2.2.2. Starting thin, I see: dkam@Omena ~/Development/rails/booko\_rails\_2.3 $ thin start > > Using rails adapter > > /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/actionpack/ > > lib/action\_dispatch/vendor/rack-1.0/rack.rb:17: warning: already > > initialized constant VERSION > > /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ > > activesupport/lib/active\_support/dependencies.rb:440:in > > `load_missing_constant': uninitialized constant ActionController::Failsafe (NameError) from /Users/dkam/Development/rails/booko_rails_2.3/vendor/rails/ activesupport/lib/active_support/dependencies.rb:80:in`const\_missing’ > > from /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ > > activesupport/lib/active\_support/inflector.rb:361:in `constantize' from /Users/dkam/Development/rails/booko_rails_2.3/vendor/rails/ activesupport/lib/active_support/inflector.rb:360:in`each’ > > from /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ > > activesupport/lib/active\_support/inflector.rb:360:in `constantize' from /Users/dkam/Development/rails/booko_rails_2.3/vendor/rails/ activesupport/lib/active_support/core_ext/string/inflections.rb:162:in`constantize’ > > from /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ > > actionpack/lib/action\_dispatch/middleware/stack.rb:58:in `==' from /Users/dkam/Development/rails/booko_rails_2.3/vendor/rails/ actionpack/lib/action_dispatch/middleware/stack.rb:97:in`index’ > > from /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ > > actionpack/lib/action\_dispatch/middleware/stack.rb:97:in > > `insert_after' ... 15 levels... from /Library/Ruby/Gems/1.8/gems/thin-1.0.0/lib/thin/runner.rb:139:in`run!’ > > from /Library/Ruby/Gems/1.8/gems/thin-1.0.0/bin/thin:6 > > from /usr/bin/thin:19:in `load’ > > from /usr/bin/thin:19 Or with Rake: dkam@Omena ~/Development/rails/booko\_rails\_2.3 $ rake middleware (in /Users/dkam/Development/rails/booko\_rails\_2.3) rake aborted! uninitialized constant ActionController::Failsafe (See full trace by running task with --trace) Starting the console returns the same error: dkam@Omena ~/Development/rails/booko\_rails\_2.3 $ ./script/console Loading development environment (Rails 2.3.2) /Users/dkam/Development/rails/booko\_rails\_2.3/vendor/rails/ activesupport/lib/active\_support/dependencies.rb:440:in `load\_missing\_constant’:NameError: uninitialized constant ActionController::Failsafe I’m running Ruby 1.8.6: $ ruby --version ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0] Any ideas on what’s causing this and how to fix it? Cheers, ---
**Author:** ![dkam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/e5b9ba/32.png) [@dkam](https://www.ruby-forum.com/u/dkam)\ **Post date:** [April 19, 2009, 11:59am UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899/2 "2009-04-19T11:59:34Z")
rename application.rb to application\_controller.eb, and next time read the changelog. ---
**Author:** ![dkam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/e5b9ba/32.png) [@dkam](https://www.ruby-forum.com/u/dkam)\ **Post date:** [April 19, 2009, 12:13pm UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899/3 "2009-04-19T12:13:10Z")
Hey Fernando, You should find this useful: > **[Rails 2.3.2 upgrade gotchas](https://thoughtbot.com/blog/rails-2-3-2-upgrade-gotchas)** > > Known issues with upgrading to Rails version 2.3.2. Schalk ---
**Author:** ![dkam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/e5b9ba/32.png) [@dkam](https://www.ruby-forum.com/u/dkam)\ **Post date:** [April 19, 2009, 12:32pm UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899/4 "2009-04-19T12:32:30Z")
Thanks for the suggestion Fernando, but that doesn’t seem to be the problem. $ ls -trlh app/controllers/ total 32 -rw-r–r-- 1 dkam dkam 890B 15 Apr 22:56 application\_controller.rb -rw-r–r-- 1 dkam dkam 11K 15 Apr 23:00 books\_controller.rb Any other thoughts? On Apr 19, 7:59 pm, Fernando P. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) ---
**Author:** ![dkam](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/e5b9ba/32.png) [@dkam](https://www.ruby-forum.com/u/dkam)\ **Post date:** [April 20, 2009, 2:13pm UTC](https://www.ruby-forum.com/t/problems-upgrading-from-2-2-2-to-2-3-2-uninitialized-constant-actioncontroller-failsafe-nameerr/165899/5 "2009-04-20T14:13:05Z")
Does anyone have any ideas what causes the “uninitialized constant ActionController::Failsafe” error? Anyone else seen this? Note - it’s not the “uninitialized constant ActionController” error caused by not renaming application.rb to application\_controller.rb Cheers, Dan