Redmine

I downloaded Redmine 2.3.1 ver.
I have this error to install bundle:

[!] There was an error parsing `Gemfile`: compile error - syntax error, unexpected ':', expecting $end
gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin, :jruby]
                             ^. Bundler cannot continue.

 #  -------------------------------------------
 #  # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 >  gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin, :jruby]
 #  gem "rbpdf", "~> 1.19.0" 
 #  -------------------------------------------

How fix it?
ps. i use ruby 2.3.1, bundler 1.12.5 and gem 2.5.1.