ASP.NET Core 1.1 Not Supporting UTF-8 Characters in Request Header

Question

We are trying to fix a problem where our application built on ASP.Net Core 1.1 deployed in an out of process hosting model, is failing with HTTP 400 "Invalid Request" when receiving a UTF-8 character in the request header. An example value passed in the request header is: "vvölker".

Just for reference, the previous support ticket is: https://developercommunity.visualstudio.com/content/problem/1095528/aspnet-core-11-and-aspnet-core-21-not-supporting-u.html

We are unable to switch to an in-process hosting model due to other constraints and hence, looking for a work around keeping the current out of process hosting model.