error when routing - ruby-on-rails

Question

I have routes defined to some static pages and also to some controllers (users and usymptoms).
When I navigate to localhost:3000/users/1 or localhost:3000/users/1/usymptoms/new everything is fine. Once I finish filling in the form on symptoms/new, I have the usymptoms controller redirecting to #users. This works fine.
In the model file, the association is users has many usymptoms and usymptoms belongs to user.
However, now my static pages are not accessible. For example, when I navigate to /learn, I get the following error:
No route matches {:action=>"new", :controller=>"usymptoms", :user_id=>nil}
I am new to rails. Can you please help me figure out the error?
I have provided my routes file and the output from "rake routes" below.
My routes.rb file
root to: 'static_pages#home'
match '/about', to: 'static_pages#about'
match '/contact', to: 'static_pages#contact'
match '/learn', to: 'static_pages#learn'
match '/signup', to: 'users#new'
match '/signin', to: 'sessions#new'
match '/signout', to: 'sessions#destroy', via: :delete
resources :users do
resources :usymptoms
end
resources :sessions, only: [:new, :create, :destroy]
======
Output from rake routes
root / static_pages#home
about /about(.:format) static_pages#about
contact /contact(.:format) static_pages#contact
learn /learn(.:format) static_pages#learn
signup /signup(.:format) users#new
signin /signin(.:format) sessions#new
signout DELETE /signout(.:format) sessions#destroy
user_usymptoms GET /users/:user_id/usymptoms(.:format) usymptoms#index
POST /users/:user_id/usymptoms(.:format) usymptoms#create
new_user_usymptom GET /users/:user_id/usymptoms/new(.:format) usymptoms#new
edit_user_usymptom GET /users/:user_id/usymptoms/:id/edit(.:format) usymptoms#edit
user_usymptom GET /users/:user_id/usymptoms/:id(.:format) usymptoms#show
PUT /users/:user_id/usymptoms/:id(.:format) usymptoms#update
DELETE /users/:user_id/usymptoms/:id(.:format) usymptoms#destroy
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
sessions POST /sessions(.:format) sessions#create
new_session GET /sessions/new(.:format) sessions#new
session DELETE /sessions/:id(.:format) sessions#destroy

Answer 1

You must have the following link somewhere: new_user_usymptom_path(#user), but #user is nil for some reason, hence the error.