Template: shim-signed/no-valid-sigs Type: error _Description: No valid UEFI Secure Boot signatures found UEFI Secure Boot is enabled on your system, but the signed shim binary in this package is not signed with a key that your system trusts. This is a FATAL ERROR - your system will not currently boot with this signed shim installed. . To fix this error, you probably need to update the trusted certificates list (DB) on your system. See . https://wiki.debian.org/SecureBoot/CAChanges . for more information about how to do this. Template: shim-signed/revoked-sig Type: error _Description: Shim signed with a revoked key UEFI Secure Boot is enabled on your system, but the signed shim binary in this package is signed by a key that has been revoked on your system. This is a FATAL ERROR - your system will not currently boot with this shim installed. . To fix this error, you probably need to update the trusted certificates revocation list (DBX) on your system. See . https://wiki.debian.org/SecureBoot/CAChanges . for more information about how to do this.