Perhaps its just that other application server frameworks have been more forgiving. Weāve just upgraded to Play Framework 2.6, which replaces Netty with Akka HTTP Server. The message appears in the logs, but it isnāt affecting functionality as far as I can see.
Well, maybe I spoke too soon. Itās being tracked here: JRACLOUD-67600. At present, that issue is in āVerifiedā status. All the same, Iām not seeing the error messages in my log file, and ngrok is showing me that much more conventional User-Agent headers are coming through from my development Jira instance.