unity launcher has no icons after returning from sleep mode

[Sascha Biermanns]

After bringing the computer into sleep mode and returning later from it, after entering my password and being back in my session, there might or might not be icons on the unity launcher. I made a screenshot from the launcher without icons.

unity:
  Installiert: 7.4.0+16.04.20160321-0ubuntu1
  Installationskandidat: 7.4.0+16.04.20160321-0ubuntu1
  Versionstabelle:
 *** 7.4.0+16.04.20160321-0ubuntu1 500
        500 http://de.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity 7.4.0+16.04.20160321-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-15.31-generic 4.4.6
Uname: Linux 4.4.0-15-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.20-0ubuntu3
Architecture: amd64
BootLog: Scanning for Btrfs filesystems
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: Thu Mar 24 19:26:34 2016
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 03) (prog-if 00 [VGA controller])
   Subsystem: Matsushita Electric Industrial Co., Ltd. Mobile GM965/GL960 Integrated Graphics Controller (primary) [10f7:8338]
   Subsystem: Matsushita Electric Industrial Co., Ltd. Mobile GM965/GL960 Integrated Graphics Controller (secondary) [10f7:8338]
InstallationDate: Installed on 2016-03-16 (8 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160307)
MachineType: Matsushita Electric Industrial Co.,Ltd. CF-19FHGAXBG
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcEnviron:
 LANGUAGE=de_DE
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-15-generic root=UUID=56c66297-9425-4cae-9a21-f0e3c231a9cf ro rootflags=subvol=@ quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/10/2007
dmi.bios.vendor: Phoenix Technologies Ltd.
dmi.bios.version: V2.00L11
dmi.board.name: CF19-2
dmi.board.vendor: Matsushita Electric Industrial Co.,Ltd.
dmi.board.version: 001
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Matsushita Electric Industrial Co.,Ltd.
dmi.chassis.version: 001
dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvrV2.00L11:bd10/10/2007:svnMatsushitaElectricIndustrialCo.,Ltd.:pnCF-19FHGAXBG:pvr002:rvnMatsushitaElectricIndustrialCo.,Ltd.:rnCF19-2:rvr001:cvnMatsushitaElectricIndustrialCo.,Ltd.:ct10:cvr001:
dmi.product.name: CF-19FHGAXBG
dmi.product.version: 002
dmi.sys.vendor: Matsushita Electric Industrial Co.,Ltd.
upstart.unity7.log: WARN 2016-03-24 19:24:37 nux.inputmethod.ibus InputMethodIBus.cpp:67 Impossible to connect to connect to ibus
version.compiz: compiz 1:0.9.12.2+16.04.20160318-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.1.2-1ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.1.2-1ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.1-1ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.1-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.6.1-1ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160218-1ubuntu3
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Thu Mar 24 19:23:24 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.18.1-1ubuntu4