Error:format name 'markdown' is already taken

[sunnycomes]

[ 2015-01-31 15:18:41.1383 30242/7f02d23bf700 Pool2/Implementation.cpp:287 ]: Could not spawn process for application /opt/redmine-2.6.1-1/apps/redmine/htdocs/: An error occured while starting up the preloader. Error ID: fe342d49 Error details saved to: /tmp/passenger-error.keWIiS Message from application: You cannot specify the same gem twice with different version requirements. You specified: redcarpet (~> 2.3.0) and redcarpet (>= 0) (Bundler::GemfileError) /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/dsl.rb:84:in gem' /opt/redmine-2.6.1-1/apps/redmine/htdocs/plugins/redmine_redcarpet_formatter/Gemfile:3:inblock in eval_gemfile' /opt/redmine-2.6.1-1/apps/redmine/htdocs/Gemfile:109:in instance_eval' /opt/redmine-2.6.1-1/apps/redmine/htdocs/Gemfile:109:inblock in eval_gemfile' /opt/redmine-2.6.1-1/apps/redmine/htdocs/Gemfile:106:in glob' /opt/redmine-2.6.1-1/apps/redmine/htdocs/Gemfile:106:ineval_gemfile' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/dsl.rb:32:in instance_eval' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/dsl.rb:32:ineval_gemfile' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/dsl.rb:10:in evaluate' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/definition.rb:25:inbuild' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler.rb:154:in definition' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler.rb:117:insetup' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/bundler-1.7.0/lib/bundler/setup.rb:17:in <top (required)>' /opt/redmine-2.6.1-1/ruby/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:135:inrequire' /opt/redmine-2.6.1-1/ruby/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:135:in rescue in require' /opt/redmine-2.6.1-1/ruby/lib/ruby/2.0.0/rubygems/core_ext/kernel_require.rb:144:inrequire' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/lib/phusion_passenger/loader_shared_helpers.rb:263:in block in run_load_path_setup_code' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/lib/phusion_passenger/loader_shared_helpers.rb:366:inrunning_bundler' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/lib/phusion_passenger/loader_shared_helpers.rb:261:in run_load_path_setup_code' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:100:inpreload_app' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:158:in <module:App>' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:29:inmodule:PhusionPassenger' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:28:in `

'

So I updated Gemfile, change gem "redcarpet" to gem "redcarpet", "~>2.3.0", but another error occurs:

[ 2015-01-31 15:24:57.0850 30916/7f04509d2700 Pool2/Implementation.cpp:287 ]: Could not spawn process for application /opt/redmine-2.6.1-1/apps/redmine/htdocs/: An error occured while starting up the preloader. Error ID: 935034bc Error details saved to: /tmp/passenger-error.EhBsZF Message from application: format name 'markdown' is already taken (ArgumentError) /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/wiki_formatting.rb:33:in register' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:361:inwiki_format_provider' /opt/redmine-2.6.1-1/apps/redmine/htdocs/plugins/redmine_redcarpet_formatter/init.rb:29:in block in <top (required)>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:75:ininstance_eval' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:75:in register' /opt/redmine-2.6.1-1/apps/redmine/htdocs/plugins/redmine_redcarpet_formatter/init.rb:23:in<top (required)>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:251:in require' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:251:inblock in require' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:236:in load_dependency' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:251:inrequire' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:150:in block in load' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:141:ineach' /opt/redmine-2.6.1-1/apps/redmine/htdocs/lib/redmine/plugin.rb:141:in load' /opt/redmine-2.6.1-1/apps/redmine/htdocs/config/initializers/30-redmine.rb:19:in<top (required)>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:245:in load' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:245:inblock in load' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:236:in load_dependency' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/activesupport-3.2.21/lib/active_support/dependencies.rb:245:inload' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/engine.rb:593:in block (2 levels) in <class:Engine>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/engine.rb:592:ineach' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/engine.rb:592:in block in <class:Engine>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/initializable.rb:30:ininstance_exec' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/initializable.rb:30:in run' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/initializable.rb:55:inblock in run_initializers' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/initializable.rb:54:in each' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/initializable.rb:54:inrun_initializers' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/application.rb:136:in initialize!' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/railties-3.2.21/lib/rails/railtie/configurable.rb:30:inmethod_missing' /opt/redmine-2.6.1-1/apps/redmine/htdocs/config/environment.rb:14:in <top (required)>' config.ru:3:inrequire' config.ru:3:in block in <main>' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:ininstance_eval' /opt/redmine-2.6.1-1/apps/redmine/htdocs/vendor/bundle/ruby/2.0.0/gems/rack-1.4.5/lib/rack/builder.rb:51:in initialize' config.ru:1:innew' config.ru:1:in <main>' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:112:ineval' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:112:in preload_app' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:158:inmodule:App' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:29:in <module:PhusionPassenger>' /opt/redmine-2.6.1-1/ruby/lib/ruby/gems/2.0.0/gems/passenger-4.0.57/helper-scripts/rack-preloader.rb:28:in

'

[sunnycomes]

I know where is the problem. My redmine(2.6.1stable) has supported markdown text formatting.