Close, minimize and resize button as well as menus are missing in window title bar in maximized mode

[Karl-Philipp Richter]

Buttons are available in non-maximized mode, menus never. This happened after connecting an external screen where buttons and menus are present and work fine.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: unity 7.4.0+16.04.20160801.2-0ubuntu1
Uname: Linux 4.7.1-040701-generic x86_64
NonfreeKernelModules: openafs
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CompizPlugins: »/apps/compiz-1/general/screen0/options/active_plugins« wurde kein Wert zugewiesen
CurrentDesktop: Unity
Date: Mon Aug 22 13:51:27 2016
DistUpgraded: 2016-03-14 15:43:39,246 DEBUG enabling apt cron job
DistroCodename: xenial
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation 3rd Gen Core processor Graphics Controller [8086:0166] (rev 09) (prog-if 00 [VGA controller])
   Subsystem: Lenovo 3rd Gen Core processor Graphics Controller [17aa:3904]
InstallationDate: Installed on 2015-12-12 (253 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
MachineType: LENOVO 20221
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.7.1-040701-generic root=UUID=791b47e7-915d-4d5a-bce0-d7e9b660a2ab ro rootflags=subvol=ubuntu-main-root
SourcePackage: unity
UpgradeStatus: Upgraded to xenial on 2016-03-14 (160 days ago)
dmi.bios.date: 07/12/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 71CN51WW(V1.21)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: INVALID
dmi.board.vendor: LENOVO
dmi.board.version: 31900003WIN8 STD MLT
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad Z500 Touch
dmi.modalias: dmi:bvnLENOVO:bvr71CN51WW(V1.21):bd07/12/2013:svnLENOVO:pn20221:pvrLenovoIdeaPadZ500Touch:rvnLENOVO:rnINVALID:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadZ500Touch:
dmi.product.name: 20221
dmi.product.version: Lenovo IdeaPad Z500 Touch
dmi.sys.vendor: LENOVO
upstart.unity-panel-service.log:
 (unity-panel-service:12701): GLib-GIO-CRITICAL **: g_dbus_proxy_call_sync_internal: assertion 'G_IS_DBUS_PROXY (proxy)' failed

 ** (unity-panel-service:12701): WARNING **: Failed to get active window:

 (unity-panel-service:12701): GLib-CRITICAL **: g_error_free: assertion 'error != NULL' failed
version.compiz: compiz 1:0.9.12.2+16.04.20160801.3-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.67-1ubuntu0.16.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 11.2.0-1ubuntu2.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.2.0-1ubuntu2.1
version.xserver-xorg-core: xserver-xorg-core 2:1.18.3-1ubuntu2.3
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
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-1build2
xserver.bootTime: Mon Aug 22 13:37:02 2016
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 5557
 vendor CMN
xserver.version: 2:1.18.3-1ubuntu2.3

[Karl-Philipp Richter (krichter722)]

One can work around this issue by running `unity --reset`<ref>http://askubuntu.com/questions/830383/how-to-restore-window-decorations-for-maximized-windows-in-unity</ref>.