illegal access to loading collection error

Question

I'm getting the error

Illegal access to loading collection

when I'm trying to get a list of variants belonging to a certain product. The NHibernate mapping is as below

<list name="Variants" lazy="false" cascade="save-update" inverse="false" table="PluginProduct_ProductVariant">
  <key column="ProductId" />
  <index column="Ordinal" />
  <one-to-many class="Plugin.Product.Business.Entities.Variant, Plugin.Product" />
</list>

I already tried chancing the laziness and inverse properties as suggested in other topics on this site, but they didn't do the trick.

I'm using NHibernate in combination with ASP.NET MVC and and I'm trying to loop through a collection of variant in my view. The view is calling the following method

        public ActionResult ShowProduct()
        {
        var id = new Guid(PluginData.PageParameters["Id"]);

        var variant = _variantService.GetVariantById(id);
        var product = variant.Product;

        return PluginView("ShowProduct.ascx", product);
        }

The above code runs without any problems. But when I debug just before returning the view I see that the list of variants which the product contains is empty. When I open more detailed debug information it's showing me the collection error.

In the view of my web application I'm trying to do the following

<%
foreach (var variant in Model.Variants)
{%>
    kleur: <%= variant.Color %>
    van: <%= variant.FromPrice %> voor: <%= variant.Price %>
<%} %>

Answer 1

Okay, very stupid, but I finally got the problem solved.

The index column Ordinal in the database wasn't getting the correct values so it was always NULL. This caused the error because NHibernate couldn't find an index column to create the list on.

Cost me a lot of time unfortunately, but glad I got it solved!