Unless you are a certified technician with access to Verifone's proprietary key-loading software, you generally fix a legitimate tamper error. Even if you clear the message, you will likely encounter a "No Keys" or "Key Error" because the encryption keys were wiped for security.

While intended to catch criminals, this error often occurs for non-malicious reasons:

Liquid exposure or extreme power surges can sometimes cause a false tamper trigger. How to Resolve the Error

Verifone terminals contain a dedicated secure microcontroller. If a firmware update was interrupted (power outage during download), the secure element can enter a “permanent error” state. A simple reboot won’t fix this. You need to:

Dropping or jarring the terminal can shift internal components and trip a sensor.

indicates that your Verifone terminal has triggered a physical security sensor