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
   RM.App.Classes._404._404Handler.TryFindContent(PublishedContentRequest contentRequest) +165
   Umbraco.Web.Routing.PublishedContentRequestEngine.HandlePublishedContent() +529
   Umbraco.Web.Routing.PublishedContentRequestEngine.FindPublishedContentAndTemplate() +250
   Umbraco.Web.Routing.PublishedContentRequestEngine.PrepareRequest() +107
   Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext) +361
   Umbraco.Web.UmbracoModule.<Init>b__8(Object sender, EventArgs e) +80
   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:4.8.4700.0