Value cannot be null. Parameter name: sessionStateBehaviorResolver - New sitecore 9.1 installation - Anyone seen this error ?

Anyone else seen this error ? I am using a version of 9.1 on .net 4.7.1 

[ArgumentNullException: Value cannot be null.
Parameter name: sessionStateBehaviorResolver]
   Sitecore.Diagnostics.Assert.ArgumentNotNull(Object argument, String argumentName) +63
   Sitecore.Owin.Extensions.AppBuilderExtensions.SetSessionStateBehaviorResolver(IAppBuilder app, SessionStateBehaviorResolver sessionStateBehaviorResolver) +54
   Sitecore.Owin.Startup.Configuration(IAppBuilder app) +28

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) +0
   System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) +128
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +142
   Owin.Loader.<>c__DisplayClass12.<MakeDelegate>b__b(IAppBuilder builder) +93
   Owin.Loader.<>c__DisplayClass1.<LoadImplementation>b__0(IAppBuilder builder) +212
   Microsoft.Owin.Host.SystemWeb.OwinAppContext.Initialize(Action`1 startup) +873
   Microsoft.Owin.Host.SystemWeb.OwinBuilder.Build(Action`1 startup) +51
   Microsoft.Owin.Host.SystemWeb.OwinHttpModule.InitializeBlueprint() +101
   System.Threading.LazyInitializer.EnsureInitializedCore(T& target, Boolean& initialized, Object& syncLock, Func`1 valueFactory) +135
   Microsoft.Owin.Host.SystemWeb.OwinHttpModule.Init(HttpApplication context) +160
   System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +581
   System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +168
   System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +277
   System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +369

[HttpException (0x80004005): Exception has been thrown by the target of an invocation.]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +532
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +111
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +714
  • Hi,

    Check your web.config I am sure it world override by any of your project web.config.

  • Hi

    As per the exception System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr)...

    I would like to tell you please check your IIS version , Sitecore 9.1 support IIS 10 + , I hope this is the root cause for this issues ,please check the prerequisite

    Internet Information Services, IIS 10 + or IIS 8.5 +

    .NET Framework 4.7.1 +

    .NET Core Runtime 2.1.3 + or later

    Microsoft PowerShell 5.1 or late

    Microsoft SQL Server 2017 or Microsoft SQL Server 2016 Service Pack

    Solr 7.2.1

  • Hi,

    Did you find out what happen? I am getting the same error on Sitecore 9.1.1.
  • In reply to Jukka-Pekka Keisala:

    This happend to me after I added a new feature to my Helix project and did not change the properties on the Web.Config to "Build action : None"
  • In my case, I resolved this error by checking web.config, I found some other process had replaced most of the file and I had to restore from a backup.