• NullReferenceException: Object reference not set to an instance of an object.

  • Ctmon.Site.WebBaseController.choose_net() in 5188Tools.cs

  • Ctmon.Site.WebBaseController.OnActionExecuting(ActionExecutingContext context) in 5188Tools.cs

  • Microsoft.AspNetCore.Mvc.Controller.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)

  • Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()

  • Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()

  • Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)

  • Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)

  • Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()

  • Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()

  • Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)

  • Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)

  • Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

• 
  
  Show raw exception details

  System.NullReferenceException: Object reference not set to an instance of an object.
     at Ctmon.Site.WebBaseController.choose_net()
     at Ctmon.Site.WebBaseController.OnActionExecuting(ActionExecutingContext context)
     at Microsoft.AspNetCore.Mvc.Controller.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
     at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()
     at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
     at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
     at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
     at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
     at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
     at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)
     at Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware.Invoke(HttpContext httpContext)
     at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

No QueryString data.