Overview Like the title claims, if you’re using ASP.NET Core and expecting the Thread.CurrentPrincipal or ClaimsPrincipal.Current to be populated you’d be wrong. This is not the IPrincipal you’re looking for. In this post we’ll discuss what happened and what you need to do now. Additionally we’ll cover all the peripheral benefits as a result of this change. History If you have ever done any .NET Framework development, you’ve probably seen the Thread class.