Problem
The following error appears on bootup:
Secure Boot Violation Error
Invalid signature detected. Check Secure Boot Policy in Setup
When booting an operating system, modern UEFI-based systems require a digital signature to ensure the operating system being booted is trusted.
Solution 1
Example is from Alienware.
Access the BIOS setup of the system (Press F2, F10, DEL, etc depending on vendor).
Access the Security menu.
Toggle the Secure Boot setting to "Disabled".
4. Attempt booting again.
Solution 2
Example is from Alienware.
Access the BIOS setup of the system (Press F2, F10, DEL, etc depending on vendor).
Access the Security menu.
Reset or Clear the cryptographic keys.
4. Attempt booting again.
Additional Information
The system image you have created may be incompatible with your BIOS configuration - that is to say, if you create a system image under legacy boot mode, it will work for both legacy and UEFI modes, but if you create a system image under UEFI mode, it will ONLY work for UEFI-mode boot.