Telerik.Sitefinity.SitefinityExceptions.ItemNotFoundException: You are trying to access Presentation item with id 7d44e1d3-7378-61ad-9066-ff000004e9e6 that no longer exists. The most probable reason is that it has been deleted by another user. at DynamicModule.ns.Wrapped_OpenAccessDynamicModuleProvider_3dcb5fe863a0467f9915b6e5f8171e6c.GetDataItem(Type itemType, Guid id) at Telerik.Sitefinity.DynamicModules.DynamicModuleManager.GetDataItem(Type itemType, Guid id) at SitefinityWebApp.PDAC.Add_Presentation_To_Calender.ProcessRequest(HttpContext context)