We deprecated a bunch of proxy APIs and CLIs with the 2.36 microversion in the Newton release. We bent over backward to make the CLI fall back to 2.35 if using a deprecated proxy in novaclient but that code is all removed now, and will be gone in the upcoming novaclient 8.0.0 release [1]. [1] https://review.openstack.org/#/c/453819/ -- Thanks, Matt