51005: Client Connection: Command or keepalive acknowledgement not received

Twilio dropped the client connection because the client did not acknowledge a command or a keepalive message within the expected time. This usually indicates an interrupted or unstable network connection between the client SDK and Twilio.

• The device lost network connectivity or switched between networks while the connection was active.
• High latency or packet loss prevented the client from responding to Twilio in time.
• The application was suspended in the background and could not process keepalive messages.
• A proxy, firewall, or other network control interrupted the persistent connection used by the SDK.
• The client application was overloaded or blocked and could not send the required acknowledgement.

• Check whether the device has a stable internet connection and test again on a reliable network.
• Make sure your application does not block the main thread or otherwise prevent the SDK from processing incoming messages.
• If your app runs on mobile devices, review background execution behavior to confirm the SDK can maintain or restore connectivity as expected.
• Verify that firewalls, proxies, or network security tools allow persistent client connections.
• Let the Twilio SDK reconnect automatically when possible and handle reconnection events in your application so the user can recover gracefully.
• If this error happens frequently, capture client-side network logs and SDK logs to identify connectivity interruptions or timeouts.

• Twilio Chat documentation
• Twilio Sync documentation