package gnome-session 3.11.4-0ubuntu1~trusty2 [origin: LP-PPA-gnome3-team-gnome3-staging] failed to install/upgrade: försöker skriva över "/usr/share/upstart/sessions/gnome-session.conf" som också finns i paketet gnome-session-bin 3.9.90-0ubuntu12

it came up wihen i started the computer

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: gnome-session 3.11.4-0ubuntu1~trusty2 [origin: LP-PPA-gnome3-team-gnome3-staging]
ProcVersionSignature: Ubuntu 3.13.0-20.42-generic 3.13.7
Uname: Linux 3.13.0-20-generic x86_64
ApportVersion: 2.14-0ubuntu1
Architecture: amd64
Date: Mon Mar 31 23:43:47 2014
DuplicateSignature: package:gnome-session:3.11.4-0ubuntu1~trusty2 [origin: LP-PPA-gnome3-team-gnome3-staging]:försöker skriva över "/usr/share/upstart/sessions/gnome-session.conf" som också finns i paketet gnome-session-bin 3.9.90-0ubuntu12
ErrorMessage: försöker skriva över "/usr/share/upstart/sessions/gnome-session.conf" som också finns i paketet gnome-session-bin 3.9.90-0ubuntu12
InstallationDate: Installed on 2014-02-24 (36 days ago)
InstallationMedia: Ubuntu-GNOME 14.04 "Trusty Tahr" - Alpha amd64 (20140218)
PackageArchitecture: all
SourcePackage: gnome-session
Title: package gnome-session 3.11.4-0ubuntu1~trusty2 [origin: LP-PPA-gnome3-team-gnome3-staging] failed to install/upgrade: försöker skriva över "/usr/share/upstart/sessions/gnome-session.conf" som också finns i paketet gnome-session-bin 3.9.90-0ubuntu12
UpgradeStatus: No upgrade log present (probably fresh install)