Server Error in '/' Application.

Sequence contains more than one matching 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 matching element

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:


[InvalidOperationException: Sequence contains more than one matching element]
   System.Linq.Enumerable.Single(IEnumerable`1 source, Func`2 predicate) +4936537
   OSG.FamilyDoctor.App_Start.ArticleVirtualNodeRouteHandler.FindContent(RequestContext requestContext, UmbracoContext umbracoContext) +326
   Umbraco.Web.Mvc.UmbracoVirtualNodeRouteHandler.GetHttpHandler(RequestContext requestContext) +32
   System.Web.Routing.UrlRoutingModule.PostResolveRequestCache(HttpContextBase context) +9943845
   System.Web.Routing.UrlRoutingModule.OnApplicationPostResolveRequestCache(Object sender, EventArgs e) +85
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +144
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +50
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +73


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