package linux-image-4.15.0-24-generic 4.15.0-24.26~16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 21

updater auto upgrade

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: linux-image-4.15.0-24-generic 4.15.0-24.26~16.04.1
ProcVersionSignature: Ubuntu 4.13.0-45.50~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-45-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
Date: Mon Jul 2 21:24:53 2018
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-trusty-amd64-osp1-20150720-0
DuplicateSignature:
 package:linux-image-4.15.0-24-generic:4.15.0-24.26~16.04.1
 Setting up linux-image-4.15.0-24-generic (4.15.0-24.26~16.04.1) ...
 Failed to create or replace /vmlinuz.old: Is a directory at /usr/bin/linux-update-symlinks line 72.
 dpkg: error processing package linux-image-4.15.0-24-generic (--configure):
  subprocess installed post-installation script returned error exit status 21
ErrorMessage: subprocess installed post-installation script returned error exit status 21
InstallationDate: Installed on 2016-03-21 (832 days ago)
InstallationMedia: Ubuntu 14.04 "Trusty" - Build amd64 LIVE Binary 20150720-04:06
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: linux-signed-hwe
Title: package linux-image-4.15.0-24-generic 4.15.0-24.26~16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 21
UpgradeStatus: No upgrade log present (probably fresh install)