ErrorMessageResourceName And ErrorMessage Can't Set Both

This is the error I'm getting using MVC2:

Either ErrorMessageString or ErrorMessageResourceName must be set, but not both.

It is coming from the [Required] Validation DataAnnotation.

Stack trace:
InvalidOperationException: Either ErrorMessageString or ErrorMessageResourceName must be set, but not both.]
System.ComponentModel.DataAnnotations.ValidationAttribute.SetupResourceAccessor() +89338
System.ComponentModel.DataAnnotations.ValidationAttribute.FormatErrorMessage(String name) +38
System.Web.Mvc.<Validate>d__1.MoveNext() +215
System.Web.Mvc.<Validate>d__5.MoveNext() +735
System.Web.Mvc.DefaultModelBinder.OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext) +424
System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +732
System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +475
System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +152
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +709
System.Web.Mvc.Controller.ExecuteCore() +162
System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__4() +58
System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +20
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +453
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +371

I've boiled my view model down to this(it breaks any time there is a [Required] attribute, works fine without):

[Required(ErrorMessage = "")]
[DataType(DataType.Text)]
[DisplayName("Property Name")]
public string MyProperty { get; set; }

My controller returns an empty ViewModel, and the form in the view is completely blank...just a submit button.