Can't Add Principals to Roles

I've run into what seems to be a bug. Using the built in user directory, I can't seem to add Principals to Roles. Instead, when I click "Save Privilege", I get an IIS yellow screen with the following stack trace:

[ArgumentNullException: Value cannot be null.
Parameter name: String]
   System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) +14198596
   System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) +177
   Inedo.ProGet.WebApplication.Pages.Administration.Security.Privileges.<>c__DisplayClass21_0.<CreateChildControls>b__6(Object s, EventArgs e) +1002
   Inedo.Web.Controls.ButtonLinks.PostBackButtonLink.OnClick(EventArgs e) +46
   Inedo.Web.Controls.ButtonLinks.PostBackButtonLink.Inedo.Web.Controls.ISimplePostControl.ProcessValidPost() +41
   Inedo.Web.PageFree.SimplePageBase.ProcessPost(IEnumerable`1 controls) +151
   Inedo.Web.PageFree.SimplePageBase.ProcessPost(IEnumerable`1 controls) +212
   Inedo.Web.PageFree.SimplePageBase.ProcessPostBack() +209
   Inedo.Web.PageFree.SimplePageBase.ProcessRequest(HttpContext context) +199
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +508
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +92

Product: ProGet
Version: 4.0.12

Thanks for the report, this will be resolved in ProGet 4.0.13, which we are releasing within the hour.

Thanks for the quick reply Steve, but I'm sorry to say after upgrading to 4.0.13, I'm still getting the same error. I've been able to work around it for now by directly adding required rows in the database.

I think we've identified this and will fix this in the next maintenance; it only impacts the free version, but you can workaround as you've noted.