Ruby on Rails App assets not loading HTTP 404 - ruby-on-rails

Question

estimatemyproject.com is running on ruby on rails for more than 2 years without any problems.
But just today it stopped loading assets .
I searched online and tried
rake assets:precompile --trace RAILS_ENV=production
but it fails:
root#emp:/home/emp/current# rake assets:precompile --trace RAILS_ENV=production
rake aborted!
/home/emp/emp/releases/20160127092918/config/application.rb:7: syntax error, unexpected ':', expecting ')'
Bundler.require(*Rails.groups(assets: %w(development test)))
^
/home/emp/emp/releases/20160127092918/config/application.rb:7: syntax error, unexpected ')', expecting kEND
Bundler.require(*Rails.groups(assets: %w(development test)))
^
/home/emp/emp/releases/20160127092918/config/application.rb:60: syntax error, unexpected $end, expecting kEND
/home/emp/emp/releases/20160127092918/Rakefile:5:in `require'
/home/emp/emp/releases/20160127092918/Rakefile:5
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:501:in `raw_load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:82:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:81:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:65:in `run'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:63:in `run'
/usr/bin/rake:27
Help me to debug this please!
Need the assets to reload or refresh the cache somehow.
Thanks!
I tried using the change diego suggested :
It gives me a different error now.
rake aborted!
no such file to load -- rubygems
/home/emp/emp/releases/20160127092918/config/boot.rb:1:in `require'
/home/emp/emp/releases/20160127092918/config/boot.rb:1
/home/emp/emp/releases/20160127092918/config/application.rb:1:in `require'
/home/emp/emp/releases/20160127092918/config/application.rb:1
/home/emp/emp/releases/20160127092918/Rakefile:5:in `require'
/home/emp/emp/releases/20160127092918/Rakefile:5
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load'
/usr/lib/ruby/vendor_ruby/rake/rake_module.rb:25:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:501:in `raw_load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:82:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:81:in `load_rakefile'
/usr/lib/ruby/vendor_ruby/rake/application.rb:65:in `run'
/usr/lib/ruby/vendor_ruby/rake/application.rb:133:in `standard_exception_handling'
/usr/lib/ruby/vendor_ruby/rake/application.rb:63:in `run'
/usr/bin/rake:27

Answer 1

You have a syntax error in config/application.rb line 7.
Seems like you're using an old version of Ruby that does not support the colon hash syntax. Change this:
Bundler.require(*Rails.groups(assets: %w(development test)))
to:
Bundler.require(*Rails.groups(:assets => %w(development test)))
Fix that and redeploy your app and rerun the rake command.