Ruby on Rails - devise users/sign_out not working

The reason for the error is that the route is inaccessible using the GET HTTP method. Notice what the relevant line looks like in your rake routes output:

destroy_user_session DELETE /users/sign_out(.:format)

Meaning that, if you want to log the user out, you need to send a DELETE request to that url. In rails, you can generate a link that does that like so:

link_to 'Sign out', destroy_user_session_path, :method => :delete

# alternatively (although NOT recommended):

link_to 'Sign out', '/users/sign_out', :method => :delete

The important part is :method => :delete. Note that a DELETE request is not really supported by browsers, rails is actually POSTing the data, but it sends a special parameter that simulates the DELETE method.

The reason behind this is that the "sign out" url is one that would log the current user out, a destructive action. If it was freely accessible through the browser, it could cause various problems. GET requests should never change the state of the server. For more information on this, here's a nice wikipedia article: http://en.wikipedia.org/wiki/REST#RESTful_web_services

Any of the above suggestions did not work for me....

This post can be more useful to find other alternatives. No route matches "/users/sign_out" devise rails 3

I had to add following lines in the application.js file

//= require_tree .
// Add following lines.
//= require jquery 
//= require jquery_ujs