system crashes with external display (after 02/28/2015 software updates)

[Felix Francis]

System crashes when connected to an external display, after software update on 02/28/2015. Everything was working perfectly before this update.

The resolution of the built in monitor is also having issues.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity-control-center 14.04.3+14.04.20140922-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-46.76-generic 3.13.11-ckt15
Uname: Linux 3.13.0-46-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Mar 1 11:40:05 2015
ExecutablePath: /usr/bin/unity-control-center
InstallationDate: Installed on 2012-05-14 (1020 days ago)
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
ProcEnviron:
 PATH=(custom, no user)
 SHELL=/bin/bash
 LANG=en_US.UTF-8
 LANGUAGE=en_US
 XDG_RUNTIME_DIR=<set>
SourcePackage: unity-control-center
UpgradeStatus: Upgraded to trusty on 2014-04-24 (310 days ago)
usr_lib_unity-control-center:
 deja-dup 30.0-0ubuntu4
 gnome-control-center 1:3.6.3-0ubuntu56.1

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Felix Francis (felixfrancier)]

Trying to change the screen resolution, every time results in the screen freezing

[Felix Francis (felixfrancier)]

installing the Intel graphics driver solved the issue

sudo apt-get install xserver-xorg-video-intel

[Bogdan Aman (bog-bt)]

Thanks. This and deleting the monitors.xml file made it work for me also.