What does this mean? How can I fix it?

Question

[InvalidOperationException: Sequence contains no elements]
   System.Linq.Enumerable.Single(IEnumerable`1 source) +317
   Ninject.Web.Mvc.NinjectMvcHttpApplicationPlugin.Start() +78
   Ninject.Infrastructure.Language.ExtensionsForIEnumerableOfT.Map(IEnumerable`1 series, Action`1 action) +159
   Ninject.Web.Common.Bootstrapper.Initialize(Func`1 createKernelCallback) +234

[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) +269
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +146
   System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters) +34
   WebActivatorEx.BaseActivationMethodAttribute.InvokeMethod() +280
   WebActivatorEx.ActivationManager.RunActivationMethods(Boolean designerMode) +759
   WebActivatorEx.ActivationManager.RunPreStartMethods(Boolean designerMode) +49
   WebActivatorEx.ActivationManager.Run() +75

[InvalidOperationException: The pre-application start initialization method Run on type WebActivatorEx.ActivationManager threw an exception with the following error message: Exception has been thrown by the target of an invocation..]
   System.Web.Compilation.BuildManager.InvokePreStartInitMethodsCore(ICollection`1 methods, Func`1 setHostingEnvironmentCultures) +890
   System.Web.Compilation.BuildManager.InvokePreStartInitMethods(ICollection`1 methods) +167
   System.Web.Compilation.BuildManager.CallPreStartInitMethods(String preStartInitListPath, Boolean& isRefAssemblyLoaded) +133
   System.Web.Compilation.BuildManager.ExecutePreAppStart() +178
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters, PolicyLevel policyLevel, Exception appDomainCreationException) +746

[HttpException (0x80004005): The pre-application start initialization method Run on type WebActivatorEx.ActivationManager threw an exception with the following error message: Exception has been thrown by the target of an invocation..]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +552
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +122
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +737

Answer 1

You code called the linq method .Single() on a collection with no entries. Maybe you wanted SingleOrDefault() if empty collection is valid.