Xorg crashed with SIGABRT in OsAbort()

[ventrical]

xorg crashes after update/upgrade and reboot. but desktop still online.

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 4.2.0-10-generic x86_64
ApportVersion: 2.19.1-0ubuntu2
Architecture: amd64
Date: Thu Oct 15 23:53:44 2015
ExecutablePath: /usr/bin/Xorg
InstallationDate: Installed on 2014-10-25 (355 days ago)
InstallationMedia: Xubuntu 14.10 "Utopic Unicorn" - Alpha amd64 (20141017)
ProcCmdline: /usr/bin/X :1 vt4 -auth /tmp/serverauth.RZIKqZNDAQ
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 OsAbort ()
 FatalError ()
 ?? ()
 xf86CloseConsole ()
 ddxGiveUp ()
Title: Xorg crashed with SIGABRT in OsAbort()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[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.