Hi developers,

Now I am trying to create register form for new members in Umbraco 5.1. I use these code in template feature.chtml:

@inherits RenderViewPage
@using System.Web.Mvc.Html;
@using Umbraco.Cms.Web;
@{
    Layout = "_Layout.cshtml";
    var formModel = new Umbraco.Cms.Web.UI.Models.RegisterModel();
    formModel.MemberTypeAlias = "client";
}

@section PageTitle
{
    @CurrentPage.Name
}
<p>@Html.Raw(@CurrentPage.content)</p>

<h2>Register form</h2>
@Html.Partial("RegisterPartial", formModel)

The register form is shown correctly. But if I try to send form, I see there error:

Value cannot be null.
Parameter name: sourceId

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: sourceId

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 

[ArgumentNullException: Value cannot be null.
Parameter name: sourceId]
   Umbraco.Framework.Mandate.That(Boolean condition, Func`2 defer) +34
   Umbraco.Framework.Persistence.Model.Associations._Revised.RelationById..ctor(HiveId sourceId, HiveId destinationId, AbstractRelationType relationType, Int32 ordinal, RelationMetaDatum[] metaData) +630
   Umbraco.Framework.Security.MembershipService`2.Create(TUserType user, MembershipCreateStatus& status) +2909
   Umbraco.Cms.Web.UI.Controllers.AuthSurfaceController.RegisterForm(RegisterModel model) +667
   lambda_method(Closure , ControllerBase , Object[] ) +127
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +264
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
   System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +129
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826266
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826266
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +826266
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +314
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +825488
   System.Web.Mvc.Controller.ExecuteCore() +159
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +335
   System.Web.Mvc.<>c__DisplayClassb.<BeginProcessRequest>b__5() +62
   System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +20
   System.Web.Mvc.<>c__DisplayClasse.<EndProcessRequest>b__d() +54
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +469
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +375

What did I do wrong?

Note: in fact a member is created with correct type = "client".