Xorg crashed with SIGABRT in OsAbort()

[puce]

After Boot and Login I opened Firefox and changed a few settings, the error came up.

ProblemType: Crash
DistroRelease: Ubuntu 15.10
Package: xserver-xorg-core 2:1.17.2-1ubuntu9
ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
Uname: Linux 4.2.0-16-generic x86_64
ApportVersion: 2.19.1-0ubuntu2
Architecture: amd64
BootLog:

CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CrashCounter: 1
CurrentDesktop: GNOME
Date: Sat Oct 17 23:01:44 2015
DistUpgraded: Fresh install
DistroCodename: wily
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company Device [103c:146d]
InstallationDate: Installed on 2015-10-17 (0 days ago)
InstallationMedia: Ubuntu-GNOME 15.10 "Wily Werewolf" - Alpha amd64 (20150924)
MachineType: Hewlett-Packard HP ProBook 6450b
ProcCmdline: /usr/bin/X vt7 -displayfd 3 -auth /run/user/120/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -verbose 3
ProcEnviron:
 SHELL=/bin/false
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.2.0-16-generic root=UUID=53be5f14-0449-4f66-bdee-68c854ed5c84 ro quiet splash vt.handoff=7
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 OsAbort ()
 FatalError ()
 ?? ()
 xf86CloseConsole ()
 ddxGiveUp ()
Title: Xorg crashed with SIGABRT in OsAbort()
UdevLog: Error: [Errno 2] Datei oder Verzeichnis nicht gefunden: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

dmi.bios.date: 07/07/2014
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68CDE Ver. F.50
dmi.board.name: 146D
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 73.16
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68CDEVer.F.50:bd07/07/2014:svnHewlett-Packard:pnHPProBook6450b:pvr:rvnHewlett-Packard:rn146D:rvrKBCVersion73.16:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP ProBook 6450b
dmi.sys.vendor: Hewlett-Packard
version.compiz: compiz N/A
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
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.xserver-xorg-core: xserver-xorg-core 2:1.17.2-1ubuntu9
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+git20150808-0ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu3
xserver.bootTime: Sun Oct 18 08:35:26 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 691
 vendor LGD
xserver.version: 2:1.17.2-1ubuntu9

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1237904, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.