Xorg assert failure: *** Error in `/usr/bin/X': free(): invalid next size (fast): 0x00007f555b0a0ba0 ***

I logged in and this error message appeared.

ProblemType: Crash
DistroRelease: Ubuntu 15.04
Package: xserver-xorg-core 2:1.17.1-0ubuntu3
ProcVersionSignature: Ubuntu 3.19.0-13.13-generic 3.19.3
Uname: Linux 3.19.0-13-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.17-0ubuntu2
Architecture: amd64
AssertionMessage: *** Error in `/usr/bin/X': free(): invalid next size (fast): 0x00007f555b0a0ba0 ***
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
Date: Mon Apr 13 11:23:40 2015
DistUpgraded: Fresh install
DistroCodename: vivid
DistroVariant: ubuntu
ExecutablePath: /usr/bin/Xorg
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 0b) (prog-if 00 [VGA controller])
   Subsystem: Acer Incorporated [ALI] Device [1025:0918]
InstallationDate: Installed on 2015-02-23 (49 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150223)
MachineType: Acer Aspire V3-371
ProcCmdline: /usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron:

ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-13-generic root=UUID=bd1db0e7-34a1-43ed-b2aa-58ff7166f763 ro quiet splash vt.handoff=7
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 __libc_message (do_abort=do_abort@entry=1, fmt=fmt@entry=0x7f55583d31a8 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
 malloc_printerr (ptr=<optimised out>, str=0x7f55583d3220 "free(): invalid next size (fast)", action=1) at malloc.c:4965
 _int_free (av=<optimised out>, p=<optimised out>, have_lock=0) at malloc.c:3834
 __GI___libc_free (mem=<optimised out>) at malloc.c:2950
 ?? () from /usr/lib/xorg/modules/input/synaptics_drv.so
Title: Xorg assert failure: *** Error in `/usr/bin/X': free(): invalid next size (fast): 0x00007f555b0a0ba0 ***
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups:

dmi.bios.date: 11/19/2014
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: V1.15
dmi.board.asset.tag: No Asset Tag
dmi.board.name: Aspire V3-371
dmi.board.vendor: Acer
dmi.board.version: V1.15
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.15
dmi.modalias: dmi:bvnInsydeCorp.:bvrV1.15:bd11/19/2014:svnAcer:pnAspireV3-371:pvrV1.15:rvnAcer:rnAspireV3-371:rvrV1.15:cvnAcer:ct10:cvrV1.15:
dmi.product.name: Aspire V3-371
dmi.product.version: V1.15
dmi.sys.vendor: Acer
version.compiz: compiz 1:0.9.12.1+15.04.20150330-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.60-2
version.libgl1-mesa-dri: libgl1-mesa-dri 10.5.2-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.5.2-0ubuntu1
version.xserver-xorg-core: xserver-xorg-core 2:1.17.1-0ubuntu3
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.9.0-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.5.0-1ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917-1~exp1ubuntu2build1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.11-1ubuntu2build1
xserver.bootTime: Tue Apr 14 15:40:30 2015
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 30784
 vendor BNQ
xserver.version: 2:1.17.1-0ubuntu3