There are a number of reasons as to why you may be receiving this error message. The first place that you should check is your error log inside your Slamdot account. The next place that you should look is within the log directory for your Rails application. Both of these locations should provide you with a better understanding of what is going wrong within your application.

Common reasons why your Rails application won’t start

1. Your public directory’s permissions are not set to 755.
2. Your dispatch.fcgi or dispatch.cgi permissions are not set to 755.
3. The first line (shebang) of your dispatch.fcgi or dispatch.cgi files are not set to #!/usr/bin/env ruby.
4. You have puts statements somewhere in your code.
5. Your database name or password is incorrect in your database.yml configuration file.

6. You have not properly enabled production mode in your environment.rb file by uncommenting **ENV[‘RAILS_ENV’]

   = ‘production’**.

7. Your RAILS_GEM_VERSION in your environment.rb is not set to the version of Rails that is installed on the server.
8. You are missing gems needed by your application.

You should first verify that your site runs under regular CGI mode before switching to FastCGI. You’ll need to restart your FastCGI processes whenever you make a change to your code while in FastCGI mode.