The new code does not work for firmware 1.23. I managed to downgrade to FW 1.12 by using SAFE MODE:
(SAFE MODE Documentation):
http://www.gwinstek.com.cn/upload/file/20181119051939962.pdf0) Clear content of USB Drive
1) Copy firmware to root directory of USB Drive
2) Insert USB Drive to scope (when it is turned off)
3) Turn on scope and immediately start rotating the VARIABLE knob until SAFE MODE shows up. It will recognize the firmware file and ask user to start installing it. If there are multiple .upg files, it will show the first one, then ask if user wants to install current one or find next firmware
4) The manual says the scope will reboot automatically, but on mine, it just stopped after showing that NAND flash was completed.
5) Reboot scope and it should boot with the firmware version you copied to the USB Drive
This process is supposed to works also for bricked scopes.
After I downgraded to 1.12, I was able to use the code to enable all the options.
Now the scope is bricked again when I tried to upgrade to latest firmware 1.23
Will try to unbrick it using the SAFE MODE with 1.12 and try again.
EDIT: Using SAFE MODE I was able to reinstall FW 1.12. Previously activated licenses are still valid.
EDIT2: upgrading to 1.23 does not work using the Utility option. It works from SAFE Mode.
EDIT3: SAFE MODE allows you to select different firmware files to use for recovery.