[spree-user] Installed spree_variant_options extension and now get NoMethodError in Spree/orders#edit

I installed the spree_variant_options extension and now when you select a
product and click 'add to cart', which takes you to /cart, a NoMethodError
in Spree/orders#edit:

Showing *
/usr/local/lib64/ruby/gems/1.9.1/gems/spree_core-1.3.2/app/views/spree/orders/_line_item.html.erb
* where line *#4* raised:

undefined method `images' for nil:NilClass

Extracted source (around line *#4*):

1: <tr class="<%= cycle('', 'alt') %> line-item">
2: <td class="cart-item-image" data-hook="cart_item_image">
3: <% if variant.images.length == 0 %>
4: <%= link_to small_image(variant.product), variant.product %>
5: <% else %>
6: <%= link_to image_tag(variant.images.first.attachment.url(:small)), variant.product %>
7: <% end %>


Anyone else run into this issue?