I created an instance configuration on Oracle Cloud based on FreeBSD-14.2-RELEASE-arm64-ufs image (could have been any other FreeBSD).
When launching an instance from this configuration, I got:
Error returned by LaunchInstance operation in Compute service.(404, NotAuthorizedOrNotFound, false) Authorization failed or requested resource not found.
Problem was: this FreeBSD image requires a VNIC display name. In the instance form, under Primary VNIC information → VNIC name (Optional) make sure you have one. It says "optional", but that's likely OCI form not recognizing actual OS image requirements.
How to debug: try to create an instance manually, not through a configuration. You will now get a different error that will point to what the problem is:
createVnicDetails.displayName size must be between 1 and 255
Additional resources: