logging with Rachel@contoso.com email breaks the app inn error system.NullReferenceException

[eliassal]

I run the application and it works like a charm. However, when I sign in with
Rachel@contoso.com/Password!1)

app breaks into visual studio with following error

'System.Web.HttpContext.Current.User.Identity.GetUserId()' threw an exception of type 'System.NullReferenceException'
Data: {System.Collections.ListDictionaryInternal}
HResult: -2147467261
HelpLink: null
InnerException: null
Message: "Object reference not set to an instance of an object."
Source: "cc53859f7132494ca0035755d0785890"
StackTrace: " at <>x.<>m0(SessionContextInterceptor <>4__this, DbConnection connection, DbConnectionInterceptionContext interceptionContext)"
TargetSite: {System.String <>m0(ContactManager.Models.SessionContextInterceptor, System.Data.Common.DbConnection, System.Data.Entity.Infrastructure.Interception.DbConnectionInterceptionContext)}

Am I missing something from config stuff? Thanks

[eliassal]

I forgot to mention that this happens when using Firefox