I am trying to enable my bot for "Everyone in your own domain". An getting this error.
If I enable it via "Specific people and group in your domain" - it works.
Does anybody have an idea what I missed?
When using the HEAD deployment, Apps script bots cannot be shared across an entire domain.
Though subtle, it is mentioned in the docs at https://developers.google.com/hangouts/chat/how-tos/bots-apps-script.
To fix this you can just create a new deployment and it should run just fine.