Redmine

I just upgraded rm 1.1.3 to latest stable release 1.2.0. I tested opening new tickets which worked as usual. But creating subtasks end with internal failure, neither the main task nor subtask are accessible. Though in gantt chart both of them are visible.

About your application's environment
Ruby version              1.8.7 (x86_64-linux)
RubyGems version          1.3.5
Rack version              1.1
Rails version             2.3.11
Active Record version     2.3.11
Active Resource version   2.3.11
Action Mailer version     2.3.11
Active Support version    2.3.11
Edge Rails revision       unknown
Application root          /usr/share/redmine-1.2.0
Environment               production
Database adapter          mysql
Database schema version   20110511000000

About your Redmine plugins
Redmine Better Gantt Chart plugin   0.5.1
Knowledgebase                       0.2.5

this is, what my apache error log gives me:

ActionView::TemplateError (Mysql::Error: Column 'lft' in order clause is ambiguous: SELECT `issues`.`id` AS t0_r0, `issues`.`tracker_id` AS t0_r1, `issues`.`project_id` AS t0_r2, `issues`.`subject` AS t0_r3, `issues`.`description` AS t0_r4, `issues`.`due_date` AS t0_r5, `issues`.`category_id` AS t0_r6, `issues`.`status_id` AS t0_r7, `issues`.`assigned_to_id` AS t0_r8, `issues`.`priority_id` AS t0_r9, `issues`.`fixed_version_id` AS t0_r10, `issues`.`author_id` AS t0_r11, `issues`.`lock_version` AS t0_r12, `issues`.`created_on` AS t0_r13, `issues`.`updated_on` AS t0_r14, `issues`.`start_date` AS t0_r15, `issues`.`done_ratio` AS t0_r16, `issues`.`estimated_hours` AS t0_r17, `issues`.`parent_id` AS t0_r18, `issues`.`root_id` AS t0_r19, `issues`.`lft` AS t0_r20, `issues`.`rgt` AS t0_r21, `issues`.`is_private` AS t0_r22, `projects`.`id` AS t1_r0, `projects`.`name` AS t1_r1, `projects`.`description` AS t1_r2, `projects`.`homepage` AS t1_r3, `projects`.`is_public` AS t1_r4, `projects`.`parent_id` AS t1_r5, `projects`.`created_on` AS t1_r6, `projects`.`updated_on` AS t1_r7, `projects`.`identifier` AS t1_r8, `projects`.`status` AS t1_r9, `projects`.`lft` AS t1_r10, `projects`.`rgt` AS t1_r11 FROM `issues`  LEFT OUTER JOIN `projects` ON `projects`.id = `issues`.project_id WHERE (((projects.status=1 AND projects.id IN (SELECT em.project_id FROM enabled_modules em WHERE em.name='issue_tracking')) AND (issues.id != 131)) AND ((issues.`lft` >= 1 AND issues.`rgt` <= 4) AND (`issues`.`root_id` = 131)))  ORDER BY `lft`) on line #72 of app/views/issues/show.rhtml:
69:   <%= link_to(l(:button_add), {:controller => 'issues', :action => 'new', :project_id => @project, :issue => {:parent_issue_id => @issue}}) if User.current.allowed_to?(:manage_subtasks, @project) %>
70: </div>
71: <p><strong><%=l(:label_subtask_plural)%></strong></p>
72: <%= render_descendants_tree(@issue) unless @issue.leaf? %>
73: </div>
74: <% end %>
75:

    app/helpers/issues_helper.rb:80:in `render_descendants_tree'
    app/views/issues/show.rhtml:72:in `_run_rhtml_app47views47issues47show46rhtml'
    app/controllers/issues_controller.rb:121
    app/controllers/issues_controller.rb:120:in `show'
    /usr/lib/ruby/1.8/phusion_passenger/rack/request_handler.rb:95:in `process_request'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_request_handler.rb:207:in `main_loop'
    /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:374:in `start_request_handler'
    /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:332:in `handle_spawn_application'
    /usr/lib/ruby/1.8/phusion_passenger/utils.rb:184:in `safe_fork'
    /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:330:in `handle_spawn_application'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `__send__'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `main_loop'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:163:in `start'
    /usr/lib/ruby/1.8/phusion_passenger/railz/application_spawner.rb:209:in `start'
    /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:262:in `spawn_rails_application'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:126:in `lookup_or_add'
    /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:256:in `spawn_rails_application'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:80:in `synchronize'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server_collection.rb:79:in `synchronize'
    /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:255:in `spawn_rails_application'
    /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:154:in `spawn_application'
    /usr/lib/ruby/1.8/phusion_passenger/spawn_manager.rb:287:in `handle_spawn_application'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `__send__'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:352:in `main_loop'
    /usr/lib/ruby/1.8/phusion_passenger/abstract_server.rb:196:in `start_synchronously'
    /usr/lib/phusion_passenger/passenger-spawn-server:61