Created attachment 1422393 [details]
The gui message
The following message should appear in GUI
2018-04-16 09:58:19.279 1 WARNING octavia.api.v2.controllers.load_balancer [req-7ac9d842-f0da-4c14-a452-124c4d880f76 - 0f03590257d3438c9bfcb9bb963347e1 - default default] Cannot delete Load Balancer 0b8af6c8-31a1-4fc6-90c7-8c5b3e9f0c2e - it has children
instead of attached file log.
Thanks for opening the bug upstream, I think that in this case there's no need to track it downstream.