Server Error in '/' Application.

Sequence contains more than one element

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.InvalidOperationException: Sequence contains more than one element

Source Error:


Line 719:                            @if (record.Source.Identifiers != null)
Line 720:                            {
Line 721:                                ChalmersResearchPublications.Models.Identifier sisbn_old = record.Identifiers.Where(x => x.Type.Id == "ed15e5ce-e2d3-42e8-8a67-a6d71acae55c").SingleOrDefault();
Line 722:                                ChalmersResearchPublications.Models.Identifier sisbn = record.Source.Identifiers.Where(x => x.Type.Id == "ed15e5ce-e2d3-42e8-8a67-a6d71acae55c").SingleOrDefault();
Line 723:                                if (sisbn != null)

Source File: c:\home\site\wwwroot\Views\PublicationPage.cshtml    Line: 721

Stack Trace:


[InvalidOperationException: Sequence contains more than one element]
   System.Linq.Enumerable.SingleOrDefault(IEnumerable`1 source) +356
   ASP._Page_Views_PublicationPage_cshtml.Execute() in c:\home\site\wwwroot\Views\PublicationPage.cshtml:721
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +198
   System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +104
   System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +78
   System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +255
   System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
   Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer) +113
   System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +291
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
   System.Web.Mvc.<>c__DisplayClass1a.<InvokeActionResultWithFilters>b__17() +23
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +245
   System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +22
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation) +245
   System.Web.Mvc.<>c__DisplayClass1c.<InvokeActionResultWithFilters>b__19() +22
   System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult) +176
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +75
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +99
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +27
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +36
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +26
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +16
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +50
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +28
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.InvokeEndHandler(IAsyncResult ar) +161
   System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +128


Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.8.4690.0