Trying to subscribe to a push topic gives unknown client

Question

Trying to use the subscribe button in the streaming api tool gives an error.

Unknown exception occurred. Removing offending listener or subscription.
[
  {
    "advice": {
      "interval": 0,
      "reconnect": "handshake"
    },
    "channel": "/meta/subscribe",
    "id": "8",
    "error": "403::Unknown client",
    "successful": false
  },
  "Invalid argument: expected subscription, not undefined"
]
8. Subscription Failure: 403::Unknown client
{
  "advice": {
    "interval": 0,
    "reconnect": "handshake"
  },
  "channel": "/meta/subscribe",
  "id": "8",
  "error": "403::Unknown client",
  "successful": false
}

Answer 1

There could be multiple reasons for this error. The troubleshooting approach I would suggest:

1. As Workbench is an open-source free tool and is not officially supported by Salesforce. Streaming API subscription with Workbench is sometimes flaky and salesforce no longer recommends using Workbench. Please use the EMP Connector, which is a Java client tool, and also open-source: github.com/forcedotcom/EMP-Connector and see if it fixes the issue. Example: https://developer.salesforce.com/docs/atlas.en-us.api_streaming.meta/api_streaming/code_sample_java_client_intro.htm

2. Ensure that your org's streaming API limit is not hitting. Details of limits mentioned in https://developer.salesforce.com/docs/atlas.en-us.api_streaming.meta/api_streaming/limits.htm

3. If you are behind a proxy, check without using it.Also, check the network logs to see if there is any network-related issue