Error when saving an EPiServer forms element

Hi, I'm trying to save/publish a selection element block, but I get a 500 error from EPiServer when im trying to publish it. This happens after I have added an element to the selection list. Have anyone else encountered this?

This also happens for the Choice element block.

EPiServer.Forms version 1.1.4.9000

Logged error message:

System.ArgumentNullException: Value cannot be null.
Parameter name: value
at System.ComponentModel.DataAnnotations.ValidationContext.set_DisplayName(String value)
at EPiServer.Validation.DataAnnotationsValidator`1.ValidateInstance(Object instance, List`1 validationResult, ValidationContext validationContext)
at EPiServer.Validation.DataAnnotationsValidator`1.ValidateInstance(Object instance, List`1 validationResult, ValidationContext validationContext)
at EPiServer.Validation.DataAnnotationsValidator`1.Validate(T instance)
at EPiServer.Validation.ValidationService.ValidateRecursively(Object instance, HashSet`1 visitedInstances)
at EPiServer.Cms.Shell.UI.Rest.ContentChangeManager.UpdateContentProperties(ContentReference contentReference, IDictionary`2 properties, SaveAction saveAction)
at EPiServer.Cms.Shell.UI.Rest.ContentDataStore.Patch(PatchContentDataModel entity)
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.b__3d()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.b__1c()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.b__1e(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult)
at EPiServer.Shell.Services.Rest.RestControllerBase.EndExecute(IAsyncResult asyncResult)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)>>>>>