Comment 4 for bug 1558866

To clarify, I already had an image uploaded with invalid architecture, and then when user tries to launch it they get the above message. Since users can upload images and fill in architecture themselves, and may be less familiar with components under the hood, better validation or alerts for glance / nova / horizon could be useful, since it doesn't seem there is validation on any of these components for architecture which can ultimately lead to the issue.

As for Mirantis, it's a vendor distribution but just uses all the same open source components from the ecosystem but pin to specific versions of components that are supposed to be stable together supposedly. The UI is horizon.