Custom error500 / 400 page in symfony 1.4

Custom 400 page:

In config/settings.yml,
all:
  .actions:
    error_404_module:       error
    error_404_action:       404

Then when a page is not found, it will forward to "<your_domain>/error/404".

Custom 500 page:

1. Create "error" folder under "config"
2. create "error.html.php" under "config/error"

Solution: route has some missing mandatory parameters

This time I encountered an error in symfony, I set a new route and got this error.
The route is like this:

new_page:
  url: /new/page/:id
  param: {module: page, action: new}
  requirements:
    id: \d+

How to fix?
1. Add a default value.

new_page:

  url: /new/page/:id

  param: {module: page, action: new, id: 0}

  requirements:

    id: \d+

2. Check if you used any routing functions like url_for2() that missing the input parameter.