Gnome does not start anymore after the installation of the new packages in RHEL6.

Issue

• Gui does not start anymore after the installation of several packages.
• At the reboot, the launch bar of Red Hat Enterprise Linux 6.7 remains white and the graphical interface does not appear.

• Tried to boot system directly in runlevel5 and using startx command in runlevel3. But getting following messages. when trying to launch gui using startx command:

  # startx
  xauth:  creating new authority file /root/.serverauth.14305
  /usr/bin/X: symbol lookup error: /usr/bin/X: undefined symbol: pixman_f_transform_bounds
  ........
  ** (gnome-settings-daemon:39940): WARNING **: /usr/lib64/libnotify.so.1: undefined symbol: gtk_widget_get_allocation
  ** (gnome-settings-daemon:39940): WARNING **: /usr/lib64/libgnome-desktop-2.so.11: undefined symbol: XRRGetOutputProperty
  ** (gnome-settings-daemon:39940): WARNING **: /usr/lib64/libxklavier.so.15: undefined symbol: _XiGetDevicePresenceNotifyEvent
  ** (gnome-settings-daemon:39940): WARNING **: /usr/lib64/libgnome-desktop-2.so.11: undefined symbol: XRRGetOutputProperty
  ** (gnome-settings-daemon:39940): WARNING **: /usr/lib64/libvorbisfile.so.3: undefined symbol: vorbis_synthesis_idheader
  /usr/bin/gnome-session: symbol lookup error: /usr/bin/gnome-session: undefined symbol: gdk_x11_display_broadcast_startup_message