View the original community article here
Last tested: Sep 2019
If a query runs forever in Action Hub, it might be because it's too large or because there are multiple streaming queries.
Try reducing size and load and see if it goes through.
Self-hosted customers might also experience issues sending/scheduling data via Action Hub and some streamed destination if your repo is not public. You might try :
Making your repo public.
Switching to a Looker-hosted instance.