A NoMethodError occurred in promises#upload_image:

  undefined method `write' for nil:NilClass
  [RAILS_ROOT]/vendor/plugins/file_column/lib/magick_file_column.rb:100:in `transform_image'

NoMethodError (undefined method `write' for nil:NilClass):
    /vendor/plugins/file_column/lib/magick_file_column.rb:100:in `transform_image'
    /vendor/plugins/file_column/lib/magick_file_column.rb:21:in `transform_with_magick'
    /vendor/plugins/file_column/lib/magick_file_column.rb:17:in `transform_with_magick'
    /vendor/plugins/file_column/lib/magick_file_column.rb:219:in `file_magick_after_assign'
    /vendor/plugins/file_column/lib/file_column.rb:657:in `file='
    /vendor/plugins/file_column/lib/file_column.rb:656:in `file='
    /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/base.rb:2117:in `attributes='
    /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/base.rb:2116:in `attributes='
    /usr/lib/ruby/gems/1.8/gems/activerecord-2.0.2/lib/active_record/base.rb:1926:in `initialize'
    /app/controllers/promises_controller.rb:284:in `upload_image'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/mime_responds.rb:106:in `respond_to'
    /app/controllers/promises_controller.rb:280:in `upload_image'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `perform_action_without_filters'
    /usr/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in `call_filters'