Display shows a generic "Err" message and beeps; no specific code number is shown.

Steps:

• Unplug the multicooker from the wall outlet and leave it disconnected for at least 5–10 minutes to allow internal capacitors to discharge.
• While unplugged, press and hold the main Start/Stop button for 10 seconds to help clear any residual logic state (if buttons are mechanical).
• Inspect the control panel for any buttons that appear stuck or physically jammed. Gently work them free if necessary.
• Plug the unit back in and attempt to select a simple program (e.g., Keep Warm or Slow Cook) with the inner pot in place and some water inside.
• If the Err message returns immediately, the control board or keypad membrane may be defective and require replacement.