According to "Ubuntu Desktop Guide"
"To maximize a window along a side of the screen, grab the titlebar and drag it to the left or right side until half of the screen is highlighted. Using the keyboard, hold down Ctrl and Super and press the Left or Right key."
Holding down Ctrl and Super and Left key works, however holding down Ctrl and Super and Right key doesn't work.
ProblemType: Bug
DistroRelease: Ubuntu 16.10
Package: unity 7.5.0+16.10.20160906.1-0ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-26.28-generic 4.8.0
Uname: Linux 4.8.0-26-generic x86_64
.tmp.unity_support_test.0:
ApportVersion: 2.20.3-0ubuntu8
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: Sat Oct 29 13:19:14 2016
DistUpgraded: Fresh install
DistroCodename: yakkety
DistroVariant: ubuntu
GraphicsCard:
Intel Corporation HD Graphics 5300 [8086:161e] (rev 09) (prog-if 00 [VGA controller])
Subsystem: Samsung Electronics Co Ltd HD Graphics 5300 [144d:c11c]
InstallationDate: Installed on 2016-10-28 (1 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
Lsusb:
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 2232:1071 Silicon Motion
Bus 001 Device 002: ID 0cf3:e300 Atheros Communications, Inc.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: SAMSUNG ELECTRONICS CO., LTD. 930X2K/931X2K
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.8.0-26-generic.efi.signed root=UUID=b11a9582-102e-45cc-95ba-109b63be95be ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 10/26/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P06AEU.084.151026.MK
dmi.board.asset.tag: No Asset Tag
dmi.board.name: NP930X2K-K01US
dmi.board.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.board.version: SGL8352A0U-C01-G001-S0001+6.3.9600
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: SAMSUNG ELECTRONICS CO., LTD.
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP06AEU.084.151026.MK:bd10/26/2015:svnSAMSUNGELECTRONICSCO.,LTD.:pn930X2K/931X2K:pvrP06AEU:rvnSAMSUNGELECTRONICSCO.,LTD.:rnNP930X2K-K01US:rvrSGL8352A0U-C01-G001-S0001+6.3.9600:cvnSAMSUNGELECTRONICSCO.,LTD.:ct9:cvrN/A:
dmi.product.name: 930X2K/931X2K
dmi.product.version: P06AEU
dmi.sys.vendor: SAMSUNG ELECTRONICS CO., LTD.
version.compiz: compiz 1:0.9.13.0+16.10.20160818.2-0ubuntu2
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.70-1
version.libgl1-mesa-dri: libgl1-mesa-dri 12.0.3-1ubuntu2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 12.0.3-1ubuntu2
version.xserver-xorg-core: xserver-xorg-core 2:1.18.4-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.10.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.7.1-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20160706-1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.12-2
xserver.bootTime: Sat Oct 29 11:01:47 2016
xserver.configfile: default
xserver.errors:
xserver.logfile: /var/log/Xorg.0.log
xserver.version: 2:1.18.4-1ubuntu6
xserver.video_driver: modeset
I use that particular keystroke all the time. I suggest you check any system settings you may have changed that affect how your hotkeys are configured.