Unity won't start on login

[Marius Gripsgard ]

Running Ubuntu Xenial Xerus.

Unity won't start.
What happens is, when I try to login it just throws me back to the login screen after a few seconds.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: xorg 1:7.7+7ubuntu4
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 358.09 Wed Oct 7 19:59:00 PDT 2015
 GCC version: gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2)
ApportVersion: 2.19.2-0ubuntu1
Architecture: amd64
BootLog:

Date: Fri Oct 30 00:43:20 2015
DistUpgraded: Fresh install
DistroCodename: xenial
DistroVariant: ubuntu
DkmsStatus:
 nvidia, 358.09, 4.2.0-16-generic, x86_64: installed
 vboxhost, 5.0.2, 4.2.0-16-generic, x86_64: installed
GraphicsCard:
 NVIDIA Corporation GM204M [GeForce GTX 980M] [10de:1617] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: CLEVO/KAPOK Computer Device [1558:7501]
InstallationDate: Installed on 2015-09-03 (56 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: Notebook P750ZM-G
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-16-generic root=UUID=68cf3293-90df-47f7-a2fa-bfd2bcb6bafd ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
Title: Xorg crash
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/31/2015
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1.03.02
dmi.board.asset.tag: Tag 12345
dmi.board.name: P750ZM-G
dmi.board.vendor: Notebook
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: Notebook
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.03.02:bd03/31/2015:svnNotebook:pnP750ZM-G:pvrNotApplicable:rvnNotebook:rnP750ZM-G:rvrNotApplicable:cvnNotebook:ct9:cvrN/A:
dmi.product.name: P750ZM-G
dmi.product.version: Not Applicable
dmi.sys.vendor: Notebook
version.compiz: compiz 1:0.9.12.2+15.10.20151015-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.65-3
version.libgl1-mesa-dri: libgl1-mesa-dri 11.0.2-1ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 11.0.2-1ubuntu4
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu10
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.2-1ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0+git20150819-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20151019-1~exp1ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Fri Oct 30 00:38:32 2015
xserver.configfile: default
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:

xserver.version: 2:1.17.2-1ubuntu10

[Sebastien Bacher (seb128)]

Thank you for your bug report. Does it work in a guest session? Could you clean ~/.cache/upstart/*.log, try to log in and add the unity logs created in the directory to the bug

[Marius Gripsgard  (mariogrip)]

I attached the unity logs from .cache/upstart.

I also noticed something weird, if i log into xfce then log back out and choose unity it starts xfce, this only happens if i have logged in to xfce and back out.

[Marius Gripsgard  (mariogrip)]

I found the problem, on do-release-upgrade it removed (I don't know why, but it's my fault to not notice that):

screen-resolution-extra:amd64 (0.17.1, automatic), libjansson4:amd64 (2.7-1ubuntu1, automatic), nvidia-settings:amd64 (358.09-0ubuntu0~gpu15.10.1, automatic), libcuda1-355:amd64 (355.11-0ubuntu0~gpu15.10.1, automatic), bbswitch-dkms:amd64 (0.7-2ubuntu1, automatic), nvidia-prime:amd64 (0.8.1, automatic), libvdpau1:amd64 (1.1.1-0ubuntu0~gpu15.10.5, automatic), libxnvctrl0:amd64 (358.09-0ubuntu0~gpu15.10.1, automatic)

I installed these packages and I also downgraded from nvidia-358.09 to nvidia-355. nvidia-358 did work before the upgrade, so I think it's the missing packages that was the problem.

Sorry for this, this was probably my fault. I was little to quick to report, before I have read the logs.