I just tried this solution and the activation still failed.
1 - Turn off printer ✔️
2 - Press STOP, LEFT, DOWN, and POWER to enter firmware mode ✔️
3 - Flash INKCHIP firmware (NW99Z9) to 100% ✔️
4 - Unplug the power ✔️
5 - Plug the power and turn on. Printer enters Recovery mode When I turned it back on, it did not enter recovery mode.
6 - Flash the INKCHIP firmware again Went ahead and turned off and put into recovery mode again to install firmware.
7 - Printer shutdown by itself after reaching 100% The printer did not shutdown by itself.
8 - Turn on printer and run INKchip activation program
9 - Immediately click the ????? button on the top left of activation program window (I believe this stops the scanning)
10 - Hit refresh and wait a few minutes to see if the printer populates in the drop-down box
11 - Once it's available, purchase the key online
12 - Click on "Activate online"
13 - Paste the code and activate! Activation still had an error
Those are the instructions that worked for me. Your experience may be different.