ASP.NET provides the Failed Request Tracing feature that allows you to capture additional diagnostic information using internal ASP.NET mechanisms. Under certain conditions, the following exceptions may appear in Sitecore log files:
Exception: System.InvalidCastException Message: Unable to cast object of type 'Sitecore.Web.SessionEndWorkerRequest' to type 'System.Web.Hosting.IIS7WorkerRequest'. Source: System.Web at System.Web.EtwTrace.Trace(EtwTraceType traceType, HttpWorkerRequest workerRequest, String data1, String data2, String data3, String data4) at System.Web.Security.Roles.IsUserInRole(String username, String roleName)
This exception occurs due to an issue in the ASP.NET Trace implementation. You can get more details from Microsoft Support by providing them the 117091416336620 ticket reference number.
You should disable failed request tracing or request a solution for issue #501928 from Microsoft Support.