Error Code Occurs During ECU Upgrade (5021-FF-0025)

Symptom: Error code 5021-FF-0025 occurs when attempting an ECU upgrade.

Cause: This error may occur if the ECU application security certificate is invalid.

Solution:

On the tablet, go to Settings > Apps > KDS 2.0 > Storage, and then select Clear data.

Restart the application and verify that it operates normally.