When a private repo is de-activated, it doesn't remove the webhook or collaborators from the repo. If you go to re-activate a private repo or re-subscribe to Hound, then the re-activation process will fail and the subscription won't be processed.  The trick to getting up and running is to remove the Hound webhook and the collaborator, which should allow you to either re-activate your private repo and subscribe successfully.

If you've tried this and you're still running into snags, feel free to holler at us by clicking on the chat window at the bottom right of the screen, and we will be happy to get this sorted for you!