OPPO players are supplied region locked to Australia.
You can region unlock DVD playback by the one off use of the OPPO super-disc. This will unlock the region locking feature and only needs to be done once. Firmware updates do not effect operation of the superdisc feature.
4K discs do not feature region locking, and can be played by all compatible players.
Blu-ray region unlocking requires a hardware modification. NOTE - These modifications are not supplied by OPPO and will void your warranty.