I just tried downgrading the firmware on an RB433 from v3.25 to v3.23 (customer request). I believe that v3.25 is the original firmware.

After reboot Winbox showed a message saying I didn't have a valid license.

Software ID changed after the downgrade. Both ID's are of the form xxxx-xxxx

The page "http://wiki.mikrotik.com/wiki/Manual:All_about_licenses" confuses me.

I don't know if there was an old key in the files store or not.

Is it possible to downgrade from v3.25 to v3.23? Should I downgrade to v3.24 first?

Good news is that upgrading back to v3.25 "restored" my key.

Vic

You can't downgrade that far, the old licensing system doesn't support the new keys.