Upgrading OPNsense is simple and easy but once the upgrade has completed, if you discover an issue with the upgrade, Is there a method to revert back to the previous OS version?
Thanks
Downgrades are generally dangerous due to the OS trying to provide "forward" compatibility but always removing functionality from "backward" releases. You may not be able to boot a system you're trying to downgrade.
ZFS snapshots / boot environments are one newer way to deal with this, but the classic way has always been trying the live image feature with an early configuration import. This will give you a full system on the new version with your actual configuration but without clobbering the disk until you think it's ok to reinstall in place with your settings intact.
Of course always make sure to back up your config.xml somewhere else just in case.
Cheers,
Franco
THANK YOU