Attachement_fu error when updating existing photos


I am attempting to replace an exiting photo with a new one uploaded by the user. I am using attachment_fu and I am coming up with the following exception:

can't convert nil into String

/vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu/backends/file_system_backend.rb:23:in `join' /vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu/backends/file_system_backend.rb:23:in `full_filename' /vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu.rb:369:in `temp_paths' /vendor/plugins/attachment_fu/lib/technoweenie/attachment_fu.rb:354:in `uploaded_data='

My ruby code: <% form_for(@photo) do |f| %>   <%= f.error_messages %>

  <%= image_tag(@photo.public_filename, :BORDER=>0) %>

  <p>   <label for="upload">Upload new photo:</label>     <%= f.file_field :uploaded_data %>     <%= f.submit 'Update' %>   </p> <% end %>

My rails code: def edit   @photo = Photo.find(params[:id]) end

def update   @photo = Photo.find(params[:id])

if @photo.update_attributes(params[:photo])       flash[:notice] = 'Photo was successfully updated.'       redirect_to('/listingHome/active/edit/' + @photo.lisitng_id) end end

Method failing in attachement_fu

# Gets the full path to the filename in this format: