The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly

I know this question already has an accepted answer, but for me, a .NET beginner, there was a simple solution to what I was doing wrong and I thought I'd share.

I had been doing this:

@Html.HiddenFor(Model.Foo.Bar.ID)

What worked for me was changing to this:

@Html.HiddenFor(m => m.Foo.Bar.ID)

(where "m" is an arbitrary string to represent the model object)

In your example, the compiler has no way of knowing what type should TModel be. You could do something close to what you are probably trying to do with an extension method.

static class ModelExtensions
{
   public static IDictionary<string, object> GetHtmlAttributes<TModel, TProperty>
      (this TModel model, Expression<Func<TModel, TProperty>> propertyExpression)
   {
       return new Dictionary<string, object>();
   }
}

But you wouldn't be able to have anything similar to virtual, I think.

EDIT:

Actually, you can do virtual, using self-referential generics:

class ModelBase<TModel>
{
    public virtual IDictionary<string, object> GetHtmlAttributes<TProperty>
        (Expression<Func<TModel, TProperty>> propertyExpression)
    {
        return new Dictionary<string, object>();
    }
}

class FooModel : ModelBase<FooModel>
{
    public override IDictionary<string, object> GetHtmlAttributes<TProperty>
        (Expression<Func<FooModel, TProperty>> propertyExpression)
    {
        return new Dictionary<string, object> { { "foo", "bar" } };
    }
}

I had this same problem, my solution:
In the web.config file :

<compilation debug="true>
had to be changed to
<compilation debug="true" targetFramework="4.0">