Getting a routing error from certain pages - ruby-on-rails

Question

I have this route
profile GET /contacts/:id(.:format) {:controller=>"my_devise/contacts", :action=>"profile"}
This is my controllers/application_controller.rb
class ApplicationController < ActionController::Base
protect_from_forgery
before_filter :get_current_user
def get_current_user
#current_user = current_user
end
end
If i have this link in my view/layouts/application.html.erb file <%= link_to "Profile", profile_path(#current_user) %> on the url http://localhost:3000/contacts/1, i have no errors, but if i try to hit the url http://localhost:3000/contacts, I get the error below
Routing Error
No route matches {:controller=>"my_devise/contacts", :action=>"profile"}
If i remove the link in my application.html.erb file and hit http://localhost:3000/contacts, the error goes away.
Why would that link cause this error?
EDIT
Full routes file
$ rake routes
users_sign_out GET /users/sign_out(.:format) {:controller=>"devise/sessions", :action=>"destroy"}
users_sign_in GET /users/sign_in(.:format) {:controller=>"my_devise/sessions", :action=>"new"}
home GET /home(.:format) {:action=>"index", :controller=>"my_devise/sessions"}
contacts GET /contacts(.:format) {:action=>"list", :controller=>"my_devise/contacts"}
profile GET /contacts/:id(.:format) {:controller=>"my_devise/contacts", :action=>"profile"}
edit_profile GET /contacts/:id/edit(.:format) {:controller=>"my_devise/contacts", :action=>"edit"}
POST /contacts/:id/edit(.:format) {:controller=>"my_devise/contacts", :action=>"update_user"}
more GET /more/:id(.:format) {:controller=>"my_devise/contacts", :action=>"more"}
POST /home(.:format) {:action=>"create_new_user", :controller=>"my_devise/sessions"}
users_sign_up GET /users/sign_up(.:format) {:controller=>"my_devise/registrations", :action=>"new"}
POST /users/sign_up(.:format) {:controller=>"my_devise/registrations", :action=>"new"}
new_user_session GET /users/sign_in(.:format) {:action=>"new", :controller=>"devise/sessions"}
user_session POST /users/sign_in(.:format) {:action=>"create", :controller=>"devise/sessions"}
destroy_user_session DELETE /users/sign_out(.:format) {:action=>"destroy", :controller=>"devise/sessions"}
user_password POST /users/password(.:format) {:action=>"create", :controller=>"devise/passwords"}
new_user_password GET /users/password/new(.:format) {:action=>"new", :controller=>"devise/passwords"}
edit_user_password GET /users/password/edit(.:format) {:action=>"edit", :controller=>"devise/passwords"}
PUT /users/password(.:format) {:action=>"update", :controller=>"devise/passwords"}
cancel_user_registration GET /users/cancel(.:format) {:action=>"cancel", :controller=>"devise/registrations"}
user_registration POST /users(.:format) {:action=>"create", :controller=>"devise/registrations"}
new_user_registration GET /users/sign_up(.:format) {:action=>"new", :controller=>"devise/registrations"}
edit_user_registration GET /users/edit(.:format) {:action=>"edit", :controller=>"devise/registrations"}
PUT /users(.:format) {:action=>"update", :controller=>"devise/registrations"}
DELETE /users(.:format) {:action=>"destroy", :controller=>"devise/registrations"}
new_user_session GET /users/sign_in(.:format) {:action=>"new", :controller=>"my_devise/sessions"}
POST /users/sign_in(.:format) {:action=>"create", :controller=>"my_devise/sessions"}
destroy_user_session DELETE /users/sign_out(.:format) {:action=>"destroy", :controller=>"my_devise/sessions"}
POST /users/password(.:format) {:action=>"create", :controller=>"devise/passwords"}
GET /users/password/new(.:format) {:action=>"new", :controller=>"devise/passwords"}
GET /users/password/edit(.:format) {:action=>"edit", :controller=>"devise/passwords"}
PUT /users/password(.:format) {:action=>"update", :controller=>"devise/passwords"}
GET /users/cancel(.:format) {:action=>"cancel", :controller=>"my_devise/registrations"}
POST /users(.:format) {:action=>"create", :controller=>"my_devise/registrations"}
GET /users/sign_up(.:format) {:action=>"new", :controller=>"my_devise/registrations"}
GET /users/edit(.:format) {:action=>"edit", :controller=>"my_devise/registrations"}
PUT /users(.:format) {:action=>"update", :controller=>"my_devise/registrations"}
DELETE /users(.:format) {:action=>"destroy", :controller=>"my_devise/registrations"}
home_index GET /home/index(.:format) {:controller=>"home", :action=>"index"}
root / {:controller=>"home", :action=>"index"}
root / {:controller=>"home", :action=>"index"}

Answer 1

To answer your actual question, it's because you don't have a route for that (/contacts - note no id). Your route is /contacts/:id(.:format) - the format is optional, but the id is not. You'll need to make the id optional, too, or create another route.

Answer 2

The routes is like this
contacts GET /contacts(.:format) {:action=>"list", :controller=>"my_devise/contacts"}
Here we have to give the format also. If we give contacts it will throw routing error. So please enter the format also.