Reverting - RMerl/asuswrt-merlin.ng GitHub Wiki

Just like flashing, reverting to an original Asus firmware is just as simple as flashing the router with a firmware downloaded from their website. The same rules apply as when flashing Asuswrt-Merlin: resetting settings might be required if going back multiple versions.

Note that starting around firmware 3.0.0.4.380_3000 (and with Asuswrt-merlin 380.60), a new firmware format is used, which will reject flashing attempts of any older version than these two versions.

Also reverting from a 382.xx version to an older 380.xx release is not officially supported - you will need to do a factory default after flashing the older release, or restore a settings backup made while still running a 380.xx release.