Server Error in '/' Application.

Error: Failed loading page http: (sometimes it will work just to ignore this error with --load-error-handling ignore)
Error: Failed loading page http://21001 (sometimes it will work just to ignore this error with --load-error-handling ignore)
Exit with code 1 due to network error: HostNotFoundError

Description: An unhandled exception occurred.

Exception Details: System.Exception: Error: Failed loading page http: (sometimes it will work just to ignore this error with --load-error-handling ignore)
Error: Failed loading page http://21001 (sometimes it will work just to ignore this error with --load-error-handling ignore)
Exit with code 1 due to network error: HostNotFoundError


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: 


[Exception: Error: Failed loading page http: (sometimes it will work just to ignore this error with --load-error-handling ignore)
Error: Failed loading page http://21001 (sometimes it will work just to ignore this error with --load-error-handling ignore)
Exit with code 1 due to network error: HostNotFoundError
]
   Rotativa.WkhtmltopdfDriver.Convert(String wkhtmltopdfPath, String switches, String html) +1052
   Rotativa.WkhtmltopdfDriver.Convert(String wkhtmltopdfPath, String switches) +59
   Rotativa.AsPdfResultBase.CallTheDriver(ControllerContext context) +105
   Rotativa.AsPdfResultBase.BuildPdf(ControllerContext context) +302
   Rotativa.AsPdfResultBase.ExecuteResult(ControllerContext context) +67
   System.Web.Mvc.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +31
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +448
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +448
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +399