Background Ubuntu 21.10 can load on my computer through secure boot, and the shim version is 15.4. Then refer to the official tutorial, I installed rEFInd v0.13.2 (the latest version when I posted this blog) via PPA in Ubuntu 21.10. However, when I restart the system and load rEFInd, it always fails with the message Verification failed:(0x1A)Security Violation. I’m sure