Hi @PrebenOlsen, The error message "DatabricksError: User XXX is not part of org: YYY" indicates that the user is not part of the organization. This error can occur when the user is removed from the organization, or there is an issue with the user's credentials.
To fix this issue, follow the steps below:
1. Check if the user is still part of the organization. If not, add the user to the organization.
2. Check if the user's credentials are correct. If not, reset the user's credentials.
3. Try using the Databricks CLI to change the cluster owner. You can use the following command:
databricks clusters update --cluster-id <cluster-id> --new-owner-username <new-owner-username>
4. If the issue persists, file a Databricks support ticket for further assistance.