package libgl1-mesa-glx:amd64 17.0.7-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

Ubuntu has started crashing and shows a black screen.,i have to force shut down to gain control

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: libgl1-mesa-glx:amd64 17.0.7-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-87.110-generic 4.4.73
Uname: Linux 4.4.0-87-generic x86_64
.tmp.unity_support_test.0:

ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Thu Jul 27 13:58:15 2017
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
DuplicateSignature:
 package:libgl1-mesa-glx:amd64:17.0.7-0ubuntu0.16.04.1
 Setting up libgl1-mesa-glx:amd64 (17.0.7-0ubuntu0.16.04.1) ...
 update-alternatives: error: cannot scan directory '/var/lib/dpkg/alternatives': No such file or directory
 dpkg: error processing package libgl1-mesa-glx:amd64 (--configure):
  subprocess installed post-installation script returned error exit status 2
ErrorMessage: subprocess installed post-installation script returned error exit status 2
GraphicsCard:
 Intel Corporation Sky Lake Integrated Graphics [8086:1916] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Skylake Integrated Graphics [103c:820c]
   Subsystem: Hewlett-Packard Company GM108M [GeForce 940MX] [103c:820c]
InstallationDate: Installed on 2017-03-23 (126 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
Lsusb:
 Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
 Bus 001 Device 003: ID 8087:0a2a Intel Corp.
 Bus 001 Device 002: ID 1bcf:2c87 Sunplus Innovation Technology Inc.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: HP HP Pavilion Notebook
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-87-generic.efi.signed root=UUID=bf1b396f-f700-4440-825b-4babfe6824d8 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.20
SourcePackage: mesa
Title: package libgl1-mesa-glx:amd64 17.0.7-0ubuntu0.16.04.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/04/2016
dmi.bios.vendor: Insyde
dmi.bios.version: F.08
dmi.board.asset.tag: Type2 - Board Asset Tag
dmi.board.name: 820C
dmi.board.vendor: HP
dmi.board.version: 82.26
dmi.chassis.type: 10
dmi.chassis.vendor: HP
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnInsyde:bvrF.08:bd07/04/2016:svnHP:pnHPPavilionNotebook:pvrType1ProductConfigId:rvnHP:rn820C:rvr82.26:cvnHP:ct10:cvrChassisVersion:
dmi.product.name: HP Pavilion Notebook
dmi.product.version: Type1ProductConfigId
dmi.sys.vendor: HP
version.compiz: compiz 1:0.9.12.2+16.04.20160823-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.76-1~ubuntu16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 12.0.6-0ubuntu0.16.04.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 17.0.7-0ubuntu0.16.04.1
version.xserver-xorg-core: xserver-xorg-core 2:1.18.4-0ubuntu0.3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160325-1ubuntu1.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Sat Jul 29 00:18:17 2017
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 1671
 vendor BOE
xserver.version: 2:1.18.4-0ubuntu0.3