rails cancan AssociationTypeMismatch

ActiveRecord::AssociationTypeMismatch (User(#70244306330580) expected, got String(#70244198919200)):
  activerecord (3.2.13) lib/active_record/associations/association.rb:204:in `raise_on_type_mismatch'
  activerecord (3.2.13) lib/active_record/associations/belongs_to_association.rb:6:in `replace'
  activerecord (3.2.13) lib/active_record/associations/singular_association.rb:17:in `writer'
  activerecord (3.2.13) lib/active_record/associations/builder/association.rb:51:in `block in define_writers'
  activerecord (3.2.13) lib/active_record/attribute_assignment.rb:85:in `block in assign_attributes'
  activerecord (3.2.13) lib/active_record/attribute_assignment.rb:78:in `each'
  activerecord (3.2.13) lib/active_record/attribute_assignment.rb:78:in `assign_attributes'
  activerecord (3.2.13) lib/active_record/base.rb:498:in `initialize'
  state_machine (1.2.0) lib/state_machine/integrations/active_record.rb:470:in `initialize'

如果遇到这个问题，那么请检查请求parameters里面是不是有一个Key-Value为"id": "",  如果有，请去掉。我这里用了cancan，配置了安全验证后，每个action都会去首先去取id为params[:id]的User。

代码：https://github.com/josevalim/inherited_resources/blob/master/lib/inherited_resources/base_helpers.rb#L51
def resource
        get_resource_ivar || set_resource_ivar(end_of_association_chain.send(method_for_find, params[:id]))
      end