Redmine

After moving a working Redmine 1.x site to another server and upgrading to 2.x, I'm getting a blank page.

Wait, don't hang up yet. I've actually done some pretty extensive investigating, and I don't think the problem is a hopelessly munged db or anything like that. That may turn out to be the case, but I don't think we're even getting that far.

Here's what I've determined:

1. Apache is correctly configured to run dispatch.fcgi. (I was getting messages in /var/log/redmine/default/*.log when I tried to load the page -- before I changed some things, anyway, but none of those changes were to the Apache config. Pretty sure that's still right.)
2. Ruby on Rails is able to connect to the correct database schema. (It wasn't at first; I fixed things, and now it is.)
3. Somewhere I read that I should be using the mysql2 connector, but that refuses to install, so I'm using just "mysql" -- but indications are that this is working fine ("rake db:version" reports: Current version: 20131005100610, and other rake db: functions seem to be working fine as well. They weren't, earlier.)
4. I'm no longer getting any messages in /var/log/redmine/default/*.log. (I was getting db connection errors in development.log, then other more ambiguous messages in production.log after I forced it into the production environment -- probably a kluge -- but now I'm getting nothing in any file. It creates development.log when I run /usr/share/redmine/public/dispatch.fcgi from a terminal, but the file is zero bytes long.)
5. Going to the home page for my Redmine site returns a blank screen -- nothing in the source code -- but I gather this is a common symptom of almost any problem that prevents Redmine from fully initializing, so tells us very little. (Hey, developers -- how about some error messages?)
6. Running ./dispatch.fcgi from the /usr/share/redmine/public/ folder gives this message: You did not specify how you would like Rails to report deprecation notices for your production environment, please set config.active_support.deprecation to :notify at config/environments/production.rb

The problem is, /usr/share/redmine/config/environments/production.rb now does specify config.active_support.deprecation exactly as requested:

# Settings specified here will take precedence over those in config/application.rb
RedmineApp::Application.configure do
  # The production environment is meant for finished, "live" apps.
  # Code is not reloaded between requests
  config.cache_classes = true

  #####
  # Customize the default logger (http://ruby-doc.org/core/classes/Logger.html)
  #
  # Use a different logger for distributed setups
  # config.logger        = SyslogLogger.new
  #
  # Rotate logs bigger than 1MB, keeps no more than 7 rotated logs around.
  # When setting a new Logger, make sure to set it's log level too.
  #
  # config.logger = Logger.new(config.log_path, 7, 1048576)
  # config.logger.level = Logger::INFO

  # Full error reports are disabled and caching is turned on
  config.action_controller.perform_caching = true

  # Enable serving of images, stylesheets, and javascripts from an asset server
  # config.action_controller.asset_host                  = "http://assets.example.com" 

  # Disable delivery errors if you bad email addresses should just be ignored
  config.action_mailer.raise_delivery_errors = false

  # No email in production log
  config.action_mailer.logger = nil

  # 2016-05-16 suggested by error message from dispatch.fcgi
  #config.active_support.deprecation = :log
  config.active_support.deprecation = :notify
end

(That's the full contents.)

So now I'm wondering what this means, and where I should be looking (or what commands I should be trying) to get more diagnostic hints. It says the file doesn't have the value set the way it is in fact set in that exact file. So is the error message wrong? Is it talking about config/environments/production.rb in some other location? Help!

script/about:

sh: 1: darcs: not found
sh: 1: hg: not found
sh: 1: cvs: not found
sh: 1: bzr: not found
Environment:
  Redmine version                2.4.2.stable
  Ruby version                   1.9.3-p484 (2013-11-22) [x86_64-linux]
  Rails version                  3.2.16
  Environment                    production
  Database adapter               MySQL
SCM:
  Subversion                     1.8.8
  Git                            1.9.1
  Filesystem                     
Redmine plugins:
  no plugin installed

This is running on Ubuntu 14.04.4 LTS.

Thanks.