Tried a simple load test of 100k WriteMessage calls from client to a separate server on same machine. The server simply echoed the message back to client. Worked brlilliantly and main thread generally kept the ui updated on both server and client. Then I tried two clients against the same server. No problems at all. 100k messages echoed back to each originating client, with server cpu load consistently about 14%. This was on my win machine, so I assume http.sys was being used, but not sure where that decision is made in the code.
Then tried same on a linux machine and it's throwing a sigsev after about 40 displayed messages echoed.
Both apps are 64 bit. Backup folder attached.