Rails s error: `method_missing': undefined method `active_record'
Solution 1
The error is clear that in config/environments/development.rb:23
you configure active_record which is not loaded.
Just remove
config.active_record.migration_error = :page_load
Will be ok.
Solution 2
Leedy Liu
is right to some degree, but if you're getting this error when you create a new Rails app, t suggests a deeper problem with your environment
According to this answer, you may have require "active_record/railtie"
commented out in your application.rb
file. Please check to make sure this is not the case
You may have to re-install Rails
with ActiveRecord
to ensure the functionality is restored with your app. Have you tried this:
gem install bundler
gem install rails
bundle install
Other than that, you need to ensure Ruby on Rails is installed correctly. What env are you running? Linux or Windows?
Solution 3
As a general fix, remove all references to active_record. Easiest way is to do a find on the root directory of "active_records", find all usages, and remove them. I found usages in config/application.rb and config/environments/development and production.rb.
Roy
Scientist, Engineer, Programmer, Analyst and Community Activist.
Updated on August 26, 2022Comments
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Roy about 1 year
My rails project works before. I got this error because I deleted mysql and everything associated mysql.
Then I reinstalled mysql. It got this error. Then I reinstalled ruby and rails. The error is still here. Using "rails new myapp", then "bundle instal", then "rails s",
I got the following error:
=> Booting WEBrick => Rails 4.0.2 application starting in development on => Run `rails server -h` for more startup options => Ctrl-C to shutdown server Exiting **/home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configuration.rb:95:in `method_missing': undefined method `active_record' for #<Rails::Application::Configuration:0x0000000303cae8> (NoMethodError) from /home/cwu/Dropbox/project/web/atop/config/environments/development.rb:23:in `block in <top (required)>'** from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:24:in `class_eval' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:24:in `configure' from /home/cwu/Dropbox/project/web/atop/config/environments/development.rb:1:in `<top (required)>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `block in require' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:214:in `load_dependency' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/activesupport-4.0.2/lib/active_support/dependencies.rb:229:in `require' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:591:in `block (2 levels) in <class:Engine>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:590:in `each' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/engine.rb:590:in `block in <class:Engine>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:30:in `instance_exec' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:30:in `run' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:55:in `block in run_initializers' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:226:in `block in tsort_each' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:348:in `block (2 levels) in each_strongly_connected_component' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:418:in `block (2 levels) in each_strongly_connected_component_from' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:427:in `each_strongly_connected_component_from' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:417:in `block in each_strongly_connected_component_from' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:44:in `each' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:44:in `tsort_each_child' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:411:in `call' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:411:in `each_strongly_connected_component_from' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:347:in `block in each_strongly_connected_component' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `each' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `call' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:345:in `each_strongly_connected_component' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:224:in `tsort_each' from /home/cwu/.rvm/rubies/ruby-2.1.0/lib/ruby/2.1.0/tsort.rb:205:in `tsort_each' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/initializable.rb:54:in `run_initializers' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/application.rb:215:in `initialize!' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configurable.rb:30:in `method_missing' from /home/cwu/Dropbox/project/web/atop/config/environment.rb:5:in `<top (required)>' from /home/cwu/Dropbox/project/web/atop/config.ru:3:in `require' from /home/cwu/Dropbox/project/web/atop/config.ru:3:in `block in <main>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize' from /home/cwu/Dropbox/project/web/atop/config.ru:in `new' from /home/cwu/Dropbox/project/web/atop/config.ru:in `<main>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:199:in `app' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands/server.rb:48:in `app' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands/server.rb:75:in `start' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:76:in `block in <top (required)>' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `tap' from /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/commands.rb:71:in `<top (required)>' from bin/rails:4:in `require' from bin/rails:4:in `<main>'
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Roy over 9 yearsThe same error. /home/cwu/.rvm/gems/ruby-2.1.0/gems/railties-4.0.2/lib/rails/railtie/configuration.rb:95:in
method_missing': undefined method
active_record' for #<Rails::Application::Configuration:0x000000044dd6f0> (NoMethodError) from /home/cwu/Dropbox/project/web/myapp/config/envir -
Roy over 9 yearsOk, after this editor. My newly created (rails new myapp) works. My old app has the same error.
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Roy over 9 yearsAfter I tried the suggestions below and come back to this suggestions, it works now. Thanks a lot.