VCS (Cisco TelePresence Video Communication Server )X8.9.2 リリースノートの、「Downgrading to an Earlier Version is Not Supported」という記載のため、ファイル更新後に切り戻す方法はないのかという問い合わせが寄せられています。
Downgrading to an Earlier Version is Not Supported
We do not support downgrades. Do not install a previous Cisco VCS version onto a system that is running a newer version.
If you do so, the system configuration will not be preserved.