No idea what happens, complains at every start-up. package linux-image-unsigned-4.15.0-22-generic (not installed) failed to install/upgrade: subprocess installed pre-removal script returned error exit status 1

[Pol del Aguila Pla]

I have no idea what is causing it, but I am prompted to report this error every time I restart my computer.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: linux-image-unsigned-4.15.0-22-generic (not installed)
ProcVersionSignature: Ubuntu 4.4.0-127.153-generic 4.4.128
Uname: Linux 4.4.0-127-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
Date: Sun Jun 10 12:28:50 2018
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
ErrorMessage: subprocess installed pre-removal script returned error exit status 1
InstallationDate: Installed on 2018-05-19 (22 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: linux-hwe-edge
Title: package linux-image-unsigned-4.15.0-22-generic (not installed) failed to install/upgrade: subprocess installed pre-removal script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)