How can I downgrade the MikroTik RouterOS™ installation to an older version?
Downgrade is possible by reinstalling the RouterOS™ from any media. The software license will be saved with the HDD as long as the disk is not repartitioned / reformatted. The configuration of the router will be lost (it is possible to save the old configuration, but this option has unpredictable results when downgrading and it is not recommended to use it). Another way is by the /system package downgrade command. This works only if you downgrade to 2.7.20 and not lower. Upload the older packages to the router via FTP and then use the /system package downgrade command.
