What has occurred if you see the message Chassis Intruded! System has halted.?

The message "Chassis Intruded! System has halted" indicates that the computer's case has been opened or tampered with, triggering a security feature designed to protect the hardware. This usually happens when the chassis intrusion detection system detects a change in the physical state of the case. To resolve this issue, you can check for any loose connections or reset the intrusion detection feature in the BiOS/UEFI settings. If necessary, ensure that the case is properly closed and restart the system.