RubyOnRails - Cannot generate new controller

I'm very new to rails and in fact this is my first blog application that I am working on. I am not able to generate a new controller as my terminal throws me

/Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/railtie/configuration.rb:95:in `method_missing': undefined method `load_defaults' for #<Rails::Application::Configuration:0x007ff653d37830> (NoMethodError)
from /Users/dilloncoffman/desktop/blog/config/application.rb:12:in `<class:Application>'
from /Users/dilloncoffman/desktop/blog/config/application.rb:10:in `<module:Blog>'
from /Users/dilloncoffman/desktop/blog/config/application.rb:9:in `<top (required)>'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:156:in `require'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:156:in `require_application_and_environment!'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:143:in `generate_or_destroy'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:60:in `generate'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands/commands_tasks.rb:49:in `run_command!'
from /Users/dilloncoffman/.rvm/gems/ruby-2.4.1/gems/railties-5.0.3/lib/rails/commands.rb:18:in `<top (required)>'
from /Users/dilloncoffman/desktop/blog/bin/rails:4:in `require'
from /Users/dilloncoffman/desktop/blog/bin/rails:4:in `<main>'

I've looked at various articles and those that have had a similar problem starting out for the past two hours. I've tried bundle update and bundle install, however nothing is working. I am trying to implement the gem mail_form into my application but ran into this error after getting installed and trying to generate a new controller for a contacts page. Any help is greatly appreciated!