how to solve ExjecJS::RuntimeError in ruby on rails

after installing fresh ruby on rails framework, if you are getting this nasty ExjecJS::RuntimeError then it feels annoying .

and when you look at console it looks like this 

after taking a closer look anyone can identify its JavaScript run-time problem , easy and best way to fix it is 

download and install node.js , it run on top of V8 ( secret behind chrome's lightening speed JavaScript engine ) 

download node.js

make sure node is accessible from Command Prompt
to check open CMD and type node -v
if its not accessible then add it to your
then navigate to your rails app directory and start rails server browse to default index.html page

you will javascript runtime is node.js V8
fix in ubuntu

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:chris-lea/node.js
sudo apt-get update
sudo apt-get install nodejs npm

or you can try some alternate methods :

• therubyracer - Google V8 embedded within Ruby
• therubyrhino - Mozilla Rhino embedded within JRuby
• Node.js
• Apple JavaScriptCore - Included with Mac OS X
• Microsoft Windows Script Host (JScript)

i hope that it helps you to fix your JS and ruby on rails problem ,if it was helpful then please share this