Model KCMS1555RSS appears to be in demo mode. How do you turn that off?

Power Failure, Demo Appears On Display And It Won'T Heat Up

https://www.aeg.co.uk > Support > Ovens
Dec 10, 2021 - 1. Switch on device and select "basic settings" using · 2. Select "demo mode" · 3. Select "off" and enter code "2468" using the up and down arrows.
Missing: MBE2658SE ‎' Must include: MBE2658SE

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  Turning AEG Command Wheel Oven Demo Mode On and Off ...

  https://www.aeg.co.uk > Support > Ovens
  Jun 2, 2020 - Demo mode allows live appliances to be demonstrated in store safely without heating up and becoming a safety risk. If you need to turn demo ...

I pressed Start/Enter and Clear/Off simultaneously for 3-5 seconds and it exited DEMO mode for me.

To turn off Demo Mode:

1. Press SETTINGS 12 times. "Demo Mode" and "ON. Press (1) to OFF" will appear in the display text area.

2. Press the "1" keypad to change the Demonstration Mode setting to Off.

3. "OFF Selected" will scroll in the text area. Demo Mode has been turned Off.

If unable to access the DEMO setting, contact Whirlpool at: https://www.whirlpool.com/services/contact-us.html

turn it on and use it the demo mode will shut off

Demonstration Mode
This is to enable you to experiment setting various
programs. (The letter D will always appear in the display
window. This is to confirm that there is no microwave
power produced and it is safe to use the oven without
any food). To set Demonstration Mode: press micro
power once, then press Stop/Cancel 4 times. To cancel
Demonstration Mode press Micro power once, then
press Stop/Cancel 4 times.

It is in the demo mode. To turn off here is what the manual says:

The microwave oven and Timer must be off. Touch and hold Timer Off or the number 3 pad (depending on model) for three to five seconds (depending upon model) until two tones sound and “d” or "Demo" (depending on model) appears on the display. Repeat to turn off and remove “d” or "Demo" icon from the display.

Try this...

Press: Function 0 2 to turn off demo mode. For future reference, Function 0 1 should turn demo mode back on.

The manual says "while in standby mode, press and hold the '3' key on the keypad for 3 seconds until 2 tones sound and the 'DEMO' icon appears. Repeat to turn demo mode off."

You can download a copy of the manual here:

http://shared.whirlpoolcorp.com/assets/pdfs/literature/Use%20and%20Care%20Guide%20-%208206572.pdf

I will need a model and serial no to further assist you

Pressing "timer/clock" button 4 times turns on and off demo mode.