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 binary in this package is signed by a key that has been revoked on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.