if subID != nil {
				msg = fmt.Sprintf("Invalid Handler for type: %v", *subID)
			}
			gridLogIf(ctx, c.queueMsg(m, muxConnectError{Error: msg}))
			return
		}
		_, _ = c.inStream.LoadOrCompute(m.MuxID, func() *muxServer {
			return newMuxStateless(ctx, m, c, *handler)
		})
	} else {
		// Stream:
		var handler *StreamHandler
		if subID == nil {
			if !m.Handler.valid() {