Failure to unlink

[Cadair]

I run unlink 1 in the control room and this turns up in the logs:

[ERROR]  WebClient:2 Failed to fetch members for the channel.                           
Nov-2 09:42:40.423 [MatrixEventHandler] error: Error handling appservice room.event Error: An API error occurred: fetch_members_failed
    at Object.platformErrorFromResult (/opt/mx-puppet-slack/node_modules/@slack/web-api/dist/errors.js:50:33)
    at WebClient.apiCall (/opt/mx-puppet-slack/node_modules/@slack/web-api/dist/WebClient.js:485:28)
    at runMicrotasks (<anonymous>)                                                      
    at processTicksAndRejections (internal/process/task_queues.js:93:5) {               
  code: 'slack_webapi_platform_error',                                                  
  data: {
    ok: false,
    error: 'fetch_members_failed',                                                      
    response_metadata: { messages: [Array], scopes: [Array], acceptedScopes: [Array] }  
  }
}

No feedback in the control room.