Secure Boot Violation” may display when Secure Boot is enabled in BIOS and attempting to boot into Ubuntu and Debian - ThinkStation - Lenovo Support CH
RMPrepUSB, Easy2Boot and USB booting: Microsoft just made Secure Boot multibooting more difficult!
Secure Boot Violation- Invalid Signature detected. Check Secure Boot - Microsoft Community
I've recently opened my Asus Laptop to find that it is telling me "Secure Boot Violation Invalid signature detected.