Validation error message is not displayed on the view

I am trying to display validation errors in the view. When i try to save this the error is raised both in the view and logs instead with my custom message additional filter type is required Here is my code

Model

 class AdditionalFilter < ActiveRecord::Base

 validates :additional_filter_type, presence:{ message: "additional filter type is required" }
 end

View

   <% if @form.errors.any? %>
        <%= @form.errors%>    <!-- i know should just display an array -->
   <%end%>

I am using Rails 4. Any help will be appreciated, or even guidance how to debug this.Thank you

Here is the error in the log

 ActiveRecord::RecordInvalid - Validation failed: Additional filters   additional filter type additional filter type is required:
 activerecord (4.2.3) lib/active_record/validations.rb:79:in   `raise_record_invalid'
 activerecord (4.2.3) lib/active_record/validations.rb:43:in `save!'