Issue:
*"Missing these required gems: pdf-writer = 1.1.8"*

config/environment.rb:
Issue:
*"Missing these required gems: pdf-writer = 1.1.8"*

config/environment.rb:

1	config.gem "pdf-writer", :lib => "pdf/writer", :version => '1.1.8'

That looks write... what's the issue? Turns out my new server didn't have the required dependencies.

I added this above the config/gem line:

1	require "#{RAILS_ROOT}/vendor/gems/pdf-writer-1.1.8/lib/pdf/writer.rb"

and saw:

1 2	no such file to load -- color no such file to load -- transaction-simple # after fixing color

the fixes:

1 2	gem install color gem install transaction-simple

remove the require line, and voila!