text: Title: [BUG] Unclear error when client cannot connect to server
  Body: A user report seeing exception:
  
  >> ConnectionError: HTTPSConnectionPool(host='###.###.com', port=443): Max retries exceeded with url: /api-token-auth/ (Caused by NewConnectionError('<urllib3.connection.VerifiedHTTPSConnection object at 0x000002047EF726C8>: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'))
  
  On connection issues during `register`/`plot`, we should provide a more understandable error