Error when subscribe Elog using web services 1.0

KennyJiang

I used example code provided from the document: ElogSubscriber.cs

When running to websocket.Connect();, it has error:
[4/8/2025 15:43:07] ERROR WebSocket.doHandshake:1554 Not a WebSocket handshake response.[4/8/2025 15:43:07] DEBUG WebSocket.doHandshake:1555
  HTTP/1.1 404 Not Found  Sec-WebSocket-Protocol: robapi2_subscription  X-Inactivity-Timeout: 300  Set-Cookie: -http-session-=6::http.session::b9cbd0389a17bba335011d7c419d6a3b; path=/; domain=127.0.0.1; httponly  Vary: Accept-Encoding  X-Frame-Options: SAMEORIGIN  X-Content-Type-Options: nosniff  X-Request-Timeout: 259200  Date: Tue, 08 Apr 2025 07:43:07 GMT  Sec-WebSocket-Accept: fxbJmtQIEKUmLRmQdxidHoJsHeo=  Cache-Control: no-cache  Content-Length: 71  X-XSS-Protection: 1; mode=block  Connection: Upgrade  Accept-Ranges: bytes  Upgrade: WebSocket    Subscription Service does not have any subscriptions for Client-ID 18.
[4/8/2025 15:43:07] DEBUG WebSocket.closeHandshake:1334 The closing was clean? False (sent: False received: False)

Any idea on how to fix this error?