Problems adding a private feature service from ArcGIS Online

I am trying to add a private feature service from ArcGIS Online that has attachments to the HTML5 viewer.

 

This is the error message:

 

Object reference not set to an instance of an object.

 

   at Geocortex.Gis.Services.ArcGisServer.Rest.ArcGisRestFeatureService.Initialize()

 

   at Geocortex.Essentials.MapService.Initialize(Boolean includeLayers)

 

   at Geocortex.Essentials.FeatureLayerService.Initialize(Boolean includeLayers)

 

   at Geocortex.Essentials.RestManager.Controllers.AddMapServiceController.a(ResultItem A_0, String[] A_1, String A_2, Nullable`1 A_3)

 

   at Geocortex.Essentials.RestManager.Controllers.AddMapServiceController.Index(ResultItem resultItem, String connectionID, String[] serviceTypes, String mapType, String[] visibleLayers, String extent, Nullable`1 drawingBehavior, Boolean addAsBaseMap)

 

   at lambda_method(Closure , ControllerBase , Object[] )

 

   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)

 

   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClassd.<InvokeActionMethodWithFilters>b__a()

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters)

 

   at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)