C:\Ruby23\blog>rails server
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:84:in `
rescue in block (2 levels) in require': There was an error while trying to load
the gem 'uglifier'. (Bundler::GemRequireError)
Gem Load Error is: Could not find a JavaScript runtime. See https://github.com/r
ails/execjs for a list of available runtimes.
Backtrace for gem load error is:
C:/Ruby23/lib/ruby/gems/2.3.0/gems/execjs-2.7.0/lib/execjs/runtimes.rb:58:in `au
todetect'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/execjs-2.7.0/lib/execjs.rb:5:in `<module:Exec
JS>'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/execjs-2.7.0/lib/execjs.rb:4:in `<top (requir
ed)>'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/uglifier-4.1.4/lib/uglifier.rb:5:in `require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/uglifier-4.1.4/lib/uglifier.rb:5:in `<top (re
quired)>'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:81:in `
require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:81:in `
block (2 levels) in require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:76:in `
each'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:76:in `
block in require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:65:in `
each'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runtime.rb:65:in `
require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler.rb:114:in `require
'
C:/Ruby23/blog/config/application.rb:7:in `<top (required)>'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/serv
er_command.rb:133:in `require'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/serv
er_command.rb:133:in `block in perform'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/serv
er_command.rb:130:in `tap'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/commands/server/serv
er_command.rb:130:in `perform'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:27:in `run'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.rb:126:in `in
voke_command'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor.rb:387:in `dispatch'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command/base.rb:63:i
n `perform'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command.rb:44:in `in
voke'
C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/commands.rb:16:in `<
top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Bundler Error Backtrace:
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runti
me.rb:80:in `block (2 levels) in require'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runti
me.rb:76:in `each'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runti
me.rb:76:in `block in require'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runti
me.rb:65:in `each'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler/runti
me.rb:65:in `require'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/bundler-1.16.1/lib/bundler.rb:11
4:in `require'
from C:/Ruby23/blog/config/application.rb:7:in `<top (required)>'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
s/server/server_command.rb:133:in `require'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
s/server/server_command.rb:133:in `block in perform'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
s/server/server_command.rb:130:in `tap'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
s/server/server_command.rb:130:in `perform'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor/command.rb:
27:in `run'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor/invocation.
rb:126:in `invoke_command'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/thor-0.20.0/lib/thor.rb:387:in `
dispatch'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
/base.rb:63:in `perform'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
.rb:44:in `invoke'
from C:/Ruby23/lib/ruby/gems/2.3.0/gems/railties-5.1.4/lib/rails/command
s.rb:16:in `<top (required)>'
from bin/rails:4:in `require'
from bin/rails:4:in `<main>'
C:\Ruby23\blog>
Help me ?