No route matches [POST] "/register/sign_up"

This is the first time that I'm receiving this error with Devise. Help me fix it. Thanks, guys!

api_base_path /api API::Base home_index_path GET /home/index(.:format) home#index api_swaggerdashboard_path GET /api/swaggerdashboard(.:format) api#swaggerdashboard new_user_session_path GET /login(.:format) devise/sessions#new user_session_path POST /login(.:format) devise/sessions#create destroy_user_session_path DELETE /logout(.:format) devise/sessions#destroy user_password_path POST /secret(.:format) devise/passwords#create new_user_password_path GET /secret/new(.:format) devise/passwords#new edit_user_password_path GET /secret/edit(.:format) devise/passwords#edit PATCH /secret(.:format) devise/passwords#update PUT /secret(.:format) devise/passwords#update cancel_user_registration_path GET /register/cancel(.:format) devise/registrations#cancel user_registration_path POST /register(.:format) devise/registrations#create new_user_registration_path GET /register/sign_up(.:format) devise/registrations#new edit_user_registration_path GET /register/edit(.:format) devise/registrations#edit PATCH /register(.:format) devise/registrations#update PUT /register(.:format) devise/registrations#update DELETE /register(.:format) devise/registrations#destroy new_admin_session_path GET /login(.:format) devise/sessions#new admin_session_path POST /login(.:format) devise/sessions#create destroy_admin_session_path DELETE /logout(.:format) devise/sessions#destroy admin_password_path POST /secret(.:format) devise/passwords#create new_admin_password_path GET /secret/new(.:format) devise/passwords#new edit_admin_password_path GET /secret/edit(.:format) devise/passwords#edit PATCH /secret(.:format) devise/passwords#update PUT /secret(.:format) devise/passwords#update cancel_admin_registration_path GET /register/cancel(.:format) devise/registrations#cancel admin_registration_path POST /register(.:format) devise/registrations#create new_admin_registration_path GET /register/sign_up(.:format) devise/registrations#new edit_admin_registration_path GET /register/edit(.:format) devise/registrations#edit PATCH /register(.:format) devise/registrations#update PUT /register(.:format) devise/registrations#update DELETE /register(.:format) devise/registrations#destroy root_path GET / home#index

http://www.catb.org/esr/faqs/smart-questions.html