Comment 0 for bug 1604657

[Regression]Unity shows blank desktop with software renderer

[Summary]
Ubuntu 16.04 LTS shows blank desktop under software renderer (llvmpipe) after updates to improve low graphics mode. (LP: #1598770)

[Expected]
Unity Desktop

[Actual]
Unity wallpaper and not much else. Launcher and panel missing, windows are immobile, no task switching. Right-click context menu works and can open terminal.

[Additional]
Observed on Ubuntu guest VM running on Windows 10 Pro host (Hyper-V). Resetting unity and compiz settings doesn't seem effective. The problem occurs whether low graphics mode is enabled in CCSM or not.

Problem appeared after completing following update
--------------------------------------------------
Changes for libunity-core-6.0-9 versions:
Installed version: 7.4.0+16.04.20160526.1-0ubuntu1
Available version: 7.4.0+16.04.20160715-0ubuntu1

Changes for unity-settings-daemon versions:
Installed version: 15.04.1+16.04.20160209-0ubuntu2
Available version: 15.04.1+16.04.20160701-0ubuntu1

Changes for libunity-settings-daemon1 versions:
Installed version: 15.04.1+16.04.20160209-0ubuntu2
Available version: 15.04.1+16.04.20160701-0ubuntu1

Changes for unity versions:
Installed version: 7.4.0+16.04.20160526.1-0ubuntu1
Available version: 7.4.0+16.04.20160715-0ubuntu1

Changes for unity-schemas versions:
Installed version: 7.4.0+16.04.20160526.1-0ubuntu1
Available version: 7.4.0+16.04.20160715-0ubuntu1

Changes for unity-services versions:
Installed version: 7.4.0+16.04.20160526.1-0ubuntu1
Available version: 7.4.0+16.04.20160715-0ubuntu1

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity 7.4.0+16.04.20160715-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic x86_64
.tmp.unity_support_test.1:

ApportVersion: 2.20.1-0ubuntu2.1
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
CurrentDesktop: Unity
Date: Tue Jul 19 22:35:43 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
GraphicsCard:

GsettingsChanges:
 b'org.compiz.core' b'active-plugins' b"['core', 'composite', 'opengl', 'resize', 'compiztoolbox', 'regex', 'move', 'grid', 'place', 'snap', 'wall', 'imgpng', 'copytex', 'mousepoll', 'vpswitch', 'commands', 'animation', 'unitymtgrabhandles', 'expo', 'session', 'fade', 'workarounds', 'ezoom', 'scale', 'unityshell']"
 b'com.canonical.Unity' b'minimize-count' b'19'
 b'com.ubuntu.user-interface' b'scale-factor' b"{'default': 8}"
 b'org.gnome.desktop.interface' b'gtk-im-module' b"'gtk-im-context-simple'"
 b'org.gnome.desktop.interface' b'scaling-factor' b'uint32 1'
InstallationDate: Installed on 2016-04-25 (85 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
Lspci:

Lsusb: Error: command ['lsusb'] failed with exit code 1:
MachineType: Microsoft Corporation Virtual Machine
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-31-generic.efi.signed root=UUID=8b0b0ff2-67f8-496f-b77b-7a50811fe8bf ro quiet splash vt.handoff=7
Renderer: Software
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/26/2012
dmi.bios.vendor: Microsoft Corporation
dmi.bios.version: Hyper-V UEFI Release v1.0
dmi.board.asset.tag: None
dmi.board.name: Virtual Machine
dmi.board.vendor: Microsoft Corporation
dmi.board.version: Hyper-V UEFI Release v1.0
dmi.chassis.asset.tag: 3900-4772-8270-5512-4576-1749-75
dmi.chassis.type: 3
dmi.chassis.vendor: Microsoft Corporation
dmi.chassis.version: Hyper-V UEFI Release v1.0
dmi.modalias: dmi:bvnMicrosoftCorporation:bvrHyper-VUEFIReleasev1.0:bd11/26/2012:svnMicrosoftCorporation:pnVirtualMachine:pvrHyper-VUEFIReleasev1.0:rvnMicrosoftCorporation:rnVirtualMachine:rvrHyper-VUEFIReleasev1.0:cvnMicrosoftCorporation:ct3:cvrHyper-VUEFIReleasev1.0:
dmi.product.name: Virtual Machine
dmi.product.version: Hyper-V UEFI Release v1.0
dmi.sys.vendor: Microsoft Corporation
version.compiz: compiz 1:0.9.12.2+16.04.20160526-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1ubuntu0.16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.3-1ubuntu2.2
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
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Tue Jul 19 22:35:01 2016
xserver.configfile: default
xserver.devices:
 input Microsoft Vmbus HID-compliant Mouse TOUCHSCREEN, id 6
 input AT Translated Set 2 keyboard KEYBOARD, id 7
xserver.errors:
 open /dev/dri/card0: No such file or directory
 AIGLX: reverting to software rendering
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.18.3-1ubuntu2.2