RAILS :"session contains objects whose class definition isn\'t available."

Question

Session contains objects whose class definition isn\'t available.
Remember to require the classes for all objects kept in the session

I am trying to integrate http://github.com/binarylogic/authlogic for authentication into my rails application . I follwed all the steps into mentioned in the documentation . Now i seem to be getting this error when i hit a controller . Looks like i am missing something obvious .

stacktrace

/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:77:in `stale_session_check!'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:61:in `load!'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/session/abstract_store.rb:28:in `[]'
/Library/Ruby/Gems/1.8/gems/authlogic-2.1.3/lib/authlogic/session/session.rb:48:in `session_credentials'
/Library/Ruby/Gems/1.8/gems/authlogic-2.1.3/lib/authlogic/session/session.rb:33:in `persist_by_session'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:178:in `send'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:178:in `evaluate_method'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:166:in `call'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:93:in `run'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:92:in `each'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:92:in `send'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:92:in `run'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:276:in `run_callbacks'
/Library/Ruby/Gems/1.8/gems/authlogic-2.1.3/lib/authlogic/session/callbacks.rb:79:in `persist'
/Library/Ruby/Gems/1.8/gems/authlogic-2.1.3/lib/authlogic/session/persistence.rb:55:in `persisting?'
/Library/Ruby/Gems/1.8/gems/authlogic-2.1.3/lib/authlogic/session/persistence.rb:39:in `find'
/Users/suryagaddipati/myprojects/groceryplanner/app/controllers/application_controller.rb:12:in `current_user_session'
/Users/suryagaddipati/myprojects/groceryplanner/app/controllers/application_controller.rb:17:in `current_user'
/Users/suryagaddipati/myprojects/groceryplanner/app/controllers/application_controller.rb:30:in `require_no_user'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:178:in `send'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:178:in `evaluate_method'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/callbacks.rb:166:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:225:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:629:in `run_before_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:615:in `call_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:610:in `perform_action_without_benchmark'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `ms'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:10:in `realtime'
/Library/Ruby/Gems/1.8/gems/activesupport-2.3.5/lib/active_support/core_ext/benchmark.rb:17:in `ms'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/rescue.rb:160:in `perform_action_without_flash'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/flash.rb:146:in `perform_action'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in `send'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:532:in `process_without_filters'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/filters.rb:606:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:391:in `process'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/base.rb:386:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/routing/route_set.rb:437:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:87:in `dispatch'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:121:in `_call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/dispatcher.rb:130:in `build_middleware_stack'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:29:in `call'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:29:in `call'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/query_cache.rb:34:in `cache'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:9:in `cache'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/query_cache.rb:28:in `call'
/Library/Ruby/Gems/1.8/gems/activerecord-2.3.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:361:in `call'
/Library/Ruby/Gems/1.8/gems/actionpack-2.3.5/lib/action_controller/string_coercion.rb:25:in `call'
/Users/suryagaddipati/.gem/ruby/1.8/gems/rack-1.0.1/lib/rack/head.rb:9:in `call'

Answer 1

Browser cookies? Are you going to tell that to all logged in users? :-)

What helped me was https://gist.github.com/1504625. Basically, change a single character in config/initializers/secret_token.rb, restart the server and you're set.

Answer 2

How are you storing your sessions? It looks like it's trying to load an old session (what you used before authlogic? Or another class that no longer exists).

Deleting all your old sessions (browser cookies if you store session in cookies) may fix the issue.