This error appears for 2 reasons on a PAX Terminal.
- The merchant is running a debit transaction and the customer enters their PIN number incorrectly. This will result in a Host Response of Invalid PIN.
- The merchant attempts to run a debit transaction and the Terminal responds with Invalid PIN.
- Check if terminal has correct Injection Keys/ Encryption
- If the terminal recently did a Firmware Update and it had not done one in several years the terminal may need to be re-encrypted.