Server Error in '/' Application.

The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult show(Int32)' in 'web.Controllers.contentsController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Parameter name: parameters

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentException: The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult show(Int32)' in 'web.Controllers.contentsController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Parameter name: parameters

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[ArgumentException: The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.Web.Mvc.ActionResult show(Int32)' in 'web.Controllers.contentsController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter.
Parameter name: parameters]
   System.Web.Mvc.ActionDescriptor.ExtractParameterFromDictionary(ParameterInfo parameterInfo, IDictionary`2 parameters, MethodInfo methodInfo) +675
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +111
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +35
   System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) +39
   System.Web.Mvc.Async.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) +71
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.AsyncInvocationWithFilters.b__3f() +72
   System.Web.Mvc.Async.<>c__DisplayClass48.b__41() +385
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.<>c__DisplayClass2b.b__1c() +38
   System.Web.Mvc.Async.<>c__DisplayClass21.b__1e(IAsyncResult asyncResult) +185
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +38
   System.Web.Mvc.Controller.b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) +29
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +52
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +36
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +38
   System.Web.Mvc.MvcHandler.b__5(IAsyncResult asyncResult, ProcessRequestState innerState) +43
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) +67
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +38
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +607
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +134


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.7.2106.0