Troubleshooting a Presto reader displaying an 'Invalid License' error. Includes diagnostics, solutions, and safety advice for commercial kiosk environments.
The license duration varies. Consult the Presto agreement.
Connectivity needs depend on the specific license validation scheme.
Contact Presto support or your vendor for licensing procedures.
License validation typically involves cryptographic verification of software authenticity. This process relies on a secure boot sequence, a trusted platform module (TPM) or secure element, and signed firmware. Failure points include: corrupted firmware, invalid cryptographic keys, clock drift affecting license validity, or communication errors with a license server (if applicable). Voltage fluctuations can corrupt memory and introduce errors into stored license data. The reader may use an asymmetric key pair to verify digital signatures on licensed features.
Ensure the device is disconnected from the power source before any cleaning or inspection. Do not use excessive force when handling cables or connectors. Be aware of potential pinch points in the kiosk environment. Use proper grounding techniques to prevent electrostatic discharge. If the device is exposed to extreme temperatures, allow it to acclimatize to room temperature before powering it on.
Regularly clean the exterior of the reader with a dry, non-abrasive cloth. Ensure adequate ventilation to prevent overheating. Check cable connections periodically for tightness and damage. Implement a scheduled power cycle routine (e.g., once per week). Monitor the reader for unusual behaviour or error messages.
Some Presto readers have a hidden diagnostic menu accessible via a specific key combination during startup. Consult the service manual for the correct sequence. Within the diagnostic menu, you may find options to reset the system clock, refresh the license, or perform a factory reset. Note: factory resets can sometimes invalidate existing licenses.