Redmine

After upgrade Redmine version from (1.2.1) to (2.0) some pages:
/projects/<My_project>/activity
/users/12
open with Error 500.

Log:

Started GET "/projects/My_project/activity" for 10.7.164.60 at 2012-05-29 15:27:57 +0400
Processing by ActivitiesController#index as HTML
  Parameters: {"id"=>"My_project"}
Completed 500 Internal Server Error in 329ms

NameError (uninitialized constant Redmine::Acts::ActivityProvider::InstanceMethods::ClassMethods::ARCondition):
  lib/redmine/activity/fetcher.rb:76:in `block (2 levels) in events'
  lib/redmine/activity/fetcher.rb:75:in `each'
  lib/redmine/activity/fetcher.rb:75:in `block in events'
  lib/redmine/activity/fetcher.rb:74:in `each'
  lib/redmine/activity/fetcher.rb:74:in `events'
  app/controllers/activities_controller.rb:41:in `index'

Started GET "/users/12" for 10.7.164.60 at 2012-05-29 15:28:36 +0400
Processing by UsersController#show as HTML
  Parameters: {"id"=>"12"}
Completed 500 Internal Server Error in 262ms

NameError (uninitialized constant Redmine::Acts::ActivityProvider::InstanceMethods::ClassMethods::ARCondition):
  lib/redmine/activity/fetcher.rb:76:in `block (2 levels) in events'
  lib/redmine/activity/fetcher.rb:75:in `each'
  lib/redmine/activity/fetcher.rb:75:in `block in events'
  lib/redmine/activity/fetcher.rb:74:in `each'
  lib/redmine/activity/fetcher.rb:74:in `events'
  app/controllers/users_controller.rb:68:in `show'

Info

Redmine 2.0.0.stable

Environment:
  Redmine version                          2.0.0.stable
  Ruby version                             1.9.3 (i386-mingw32)
  Rails version                            3.2.3
  Environment                              production
  Database adapter                         PostgreSQL
Redmine plugins:
  redmine_auto_percent                     0.0.1
  redmine_lightbox                         0.0.1
  redmine_wiki_gchart_formula              0.0.2

Redmine Auto Done 100%

Automatically sets 100% done on Resolved or Closed
  Wade Womersley 0.0.1  
Redmine Light Box plugin

Lightbox for attachments

https://github.com/zipme/redmine_lightbox
  G.K. 0.0.1  
Redmine Wiki Gchart LaTeX-style Formula plugin

This plugin enables Redmine to render LaTeX-style formula images in Wiki.

https://github.com/masamitsu-murase/redmine_wiki_gchart_formula/
  Masamitsu MURASE 0.0.2