Ubuntu – Stuck in Unity 2d, 12.04

Since applying some fixes to Ubuntu 12.04 after being horribly stuck, I noticed when I login to Unity 3D, I enter Unity 2D (both entries are available at login). Unity 3D seems to be completely missing.

• nick@nick:~$ /usr/lib/nux/unity_support_test -p shows:

  Xlib: extension "GLX" missing on display ":0.0".
  Error: GLX is not available on the system

• Unity 3D worked perfectly before.

My technical knowledge is limited so I find it hard to compare my question with those already asked on the site. Additional info about what happened before this issue came up may be due to some chaotic removal and installation of stuff without reasons I understand. Info here and maybe this sheds some light. I did reïnstall the packages marked as remove:

Start-Date: 2013-12-07 02:00:03
Commandline: apt-get install libqt4-dev intltool

Install: libx11-xcb-dev:amd64 (1.4.99.1-0ubuntu2.2, automatic), libxdamage-dev:amd64 (1.1.3-2build1, automatic), libqt4-opengl-dev:amd64 (4.8.1-0ubuntu4.4, automatic), libpthread-stubs0:amd64 (0.3-3, automatic), libxfixes-dev:amd64 (5.0-4ubuntu4.1, automatic), libgl1-mesa-dev:amd64 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), xserver-xorg-core:amd64 (1.12.3+git20120709+server-1.12-branch.60e0d205-0ubuntu0ricotz~precise, automatic), libxcb-dri2-0-dev:amd64 (1.8.1-1ubuntu0.2, automatic), libgl1-mesa-glx:amd64 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), libgl1-mesa-glx:i386 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), libglapi-mesa:amd64 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), libglapi-mesa:i386 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), libxxf86vm-dev:amd64 (1.1.1-2ubuntu0.1, automatic), x11proto-kb-dev:amd64 (1.0.5-2, automatic), x11proto-gl-dev:amd64 (1.4.16-1, automatic), mesa-common-dev:amd64 (9.2.0~git20131002+9.2.2eb55601-0ubuntu0sarvatt~precise, automatic), xtrans-dev:amd64 (1.2.6-2, automatic), libqt4-dev:amd64 (4.8.1-0ubuntu4.4), x11proto-input-dev:amd64 (2.1.99.6-1, automatic), x11proto-fixes-dev:amd64 (5.0-2ubuntu1, automatic), xserver-xorg-input-evdev:amd64 (2.7.0+git20120504.f28507e8-0ubuntu0sarvatt~precise, automatic), libglu1-mesa-dev:amd64 (9.0.0-0ubuntu1~precise1, automatic), libdrm-dev:amd64 (2.4.46+git20130702.c6d73cfe-0ubuntu0sarvatt~precise, automatic), x11proto-xf86vidmode-dev:amd64 (2.3.1-2, automatic), x11proto-xext-dev:amd64 (7.2.0-3, automatic), qt4-qmake:amd64 (4.8.1-0ubuntu4.4, automatic), libxext-dev:amd64 (1.3.0-3ubuntu0.1, automatic), libxcb-glx0-dev:amd64 (1.8.1-1ubuntu0.2, automatic), x11proto-damage-dev:amd64 (1.2.1-2, automatic), libqtwebkit-dev:amd64 (2.2.1-1ubuntu4, automatic), libxau-dev:amd64 (1.0.6-4, automatic), qt4-linguist-tools:amd64 (4.8.1-0ubuntu4.4, automatic), xorg-sgml-doctools:amd64 (1.10-1, automatic), libx11-dev:amd64 (1.4.99.1-0ubuntu2.2, automatic), libx11-doc:amd64 (1.4.99.1-0ubuntu2.2, automatic), libkms1:amd64 (2.4.46+git20130702.c6d73cfe-0ubuntu0sarvatt~precise, automatic), libxcb1-dev:amd64 (1.8.1-1ubuntu0.2, automatic), x11proto-core-dev:amd64 (7.0.22-1ubuntu0.1, automatic), x11proto-dri2-dev:amd64 (2.8-1, automatic), libxdmcp-dev:amd64 (1.1.0-4, automatic), libpthread-stubs0-dev:amd64 (0.3-3, automatic)

Remove: xserver-common-lts-raring:amd64 (1.13.3-0ubuntu6~precise3), ubuntu-desktop:amd64 (1.267.1), xserver-xorg-input-all-lts-raring:amd64 (7.7+1ubuntu4~precise1), xserver-xorg-video-vmware-lts-raring:amd64 (12.0.2+git.e5ac80d8-0ubuntu1~precise1), xserver-xorg-video-modesetting-lts-raring:amd64 (0.7.0-0ubuntu2~precise1), xserver-xorg-video-ati-lts-raring:amd64 (7.1.0-0ubuntu2~precise1), xserver-xorg-video-r128-lts-raring:amd64 (6.9.1-0ubuntu1~precise1), xserver-xorg-video-nouveau-lts-raring:amd64 (1.0.7-0ubuntu1~precise1), xserver-xorg-input-mouse-lts-raring:amd64 (1.7.2-3~precise1), x11-xserver-utils-lts-raring:amd64 (7.7~3ubuntu2~precise1), xserver-xorg-input-evdev-lts-raring:amd64 (2.7.3-0ubuntu2b2~precise1), xserver-xorg-video-all-lts-raring:amd64 (7.7+1ubuntu4~precise1), xserver-xorg-video-cirrus-lts-raring:amd64 (1.5.2-0ubuntu1~precise1), xserver-xorg-input-synaptics-lts-raring:amd64 (1.6.2-1ubuntu6~precise1), libgl1-mesa-glx-lts-raring:amd64 (9.1.7-1ubuntu2~precise1), libgl1-mesa-glx-lts-raring:i386 (9.1.7-1ubuntu2~precise1), xserver-xorg-video-mach64-lts-raring:amd64 (6.9.3-0ubuntu1~precise1), xserver-xorg-video-s3-lts-raring:amd64 (0.6.5-0ubuntu3~precise1), xserver-xorg-video-vesa-lts-raring:amd64 (2.3.2-0ubuntu1~precise1), xserver-xorg-video-tdfx-lts-raring:amd64 (1.4.5-0ubuntu1~precise1), xserver-xorg-video-sisusb-lts-raring:amd64 (0.9.6-0ubuntu1~precise1), xserver-xorg-video-radeon-lts-raring:amd64 (7.1.0-0ubuntu2~precise1), xserver-xorg-video-trident-lts-raring:amd64 (1.3.6-0ubuntu2~precise1), libxatracker1-lts-raring:amd64 (9.1.7-1ubuntu2~precise1), xserver-xorg-input-wacom-lts-raring:amd64 (0.19.0-0ubuntu1~precise1), xserver-xorg-video-mga-lts-raring:amd64 (1.6.2-0ubuntu1~precise1), libgl1-mesa-dri-lts-raring:amd64 (9.1.7-1ubuntu2~precise1), libgl1-mesa-dri-lts-raring:i386 (9.1.7-1ubuntu2~precise1), xserver-xorg-lts-raring:amd64 (7.7+1ubuntu4~precise1), xserver-xorg-video-fbdev-lts-raring:amd64 (0.4.3-0ubuntu1~precise1), xserver-xorg-core-lts-raring:amd64 (1.13.3-0ubuntu6~precise3), xserver-xorg-input-vmmouse-lts-raring:amd64 (12.9.0-0ubuntu3~precise1), xorg:amd64 (7.6+12ubuntu2), xserver-xorg-video-neomagic-lts-raring:amd64 (1.2.7-0ubuntu1~precise1), xserver-xorg-video-openchrome-lts-raring:amd64 (0.3.1-0ubuntu1~precise1), xserver-xorg-video-sis-lts-raring:amd64 (0.10.7-0ubuntu1~precise1), xserver-xorg-video-savage-lts-raring:amd64 (2.3.6-0ubuntu1~precise1), xserver-xorg-video-intel-lts-raring:amd64 (2.21.6-0ubuntu4.3~precise1), libglapi-mesa-lts-raring:amd64 (9.1.7-1ubuntu2~precise1), libglapi-mesa-lts-raring:i386 (9.1.7-1ubuntu2~precise1), xserver-xorg-video-siliconmotion-lts-raring:amd64 (1.7.7-0ubuntu1~precise1)
End-Date: 2013-12-07 02:01:39

Very sorry for the chaotic way this looks.

Edit:
As mentioned, all the removed packages got reïnstalled. It seemed logical to run
sudo dpkg-reconfigure xserver-xorg
like I found in the last link you provided. This gave me the output:

Building dependency tree
Reading state information… Done
The following packages were automatically installed and are no longer required:
x11-apps linux-headers-3.2.0-56 x11-session-utils x11-xfs-utils
linux-headers-3.2.0-56-generic xinit libfs6 libllvm3.3
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
libgl1-mesa-glx libgl1-mesa-glx:i386 libglapi-mesa libglapi-mesa:i386
xserver-xorg-core xserver-xorg-input-evdev
Suggested packages:
xfonts-100dpi xfonts-75dpi
The following packages will be REMOVED:
libgl1-mesa-dri-lts-raring libgl1-mesa-dri-lts-raring:i386
libgl1-mesa-glx-lts-raring libgl1-mesa-glx-lts-raring:i386
libglapi-mesa-lts-raring libglapi-mesa-lts-raring:i386
libxatracker1-lts-raring ubuntu-desktop x11-xserver-utils-lts-raring xorg
xserver-common-lts-raring xserver-xorg-core-lts-raring
xserver-xorg-input-all-lts-raring xserver-xorg-input-evdev-lts-raring
xserver-xorg-input-mouse-lts-raring xserver-xorg-input-synaptics-lts-raring
xserver-xorg-input-vmmouse-lts-raring xserver-xorg-input-wacom-lts-raring
xserver-xorg-lts-raring xserver-xorg-video-all-lts-raring
xserver-xorg-video-ati-lts-raring xserver-xorg-video-cirrus-lts-raring
xserver-xorg-video-fbdev-lts-raring xserver-xorg-video-intel-lts-raring
xserver-xorg-video-mach64-lts-raring xserver-xorg-video-mga-lts-raring
xserver-xorg-video-modesetting-lts-raring
xserver-xorg-video-neomagic-lts-raring xserver-xorg-video-nouveau-lts-raring
xserver-xorg-video-openchrome-lts-raring xserver-xorg-video-r128-lts-raring
xserver-xorg-video-radeon-lts-raring xserver-xorg-video-s3-lts-raring
xserver-xorg-video-savage-lts-raring
xserver-xorg-video-siliconmotion-lts-raring
xserver-xorg-video-sis-lts-raring xserver-xorg-video-sisusb-lts-raring
xserver-xorg-video-tdfx-lts-raring xserver-xorg-video-trident-lts-raring
xserver-xorg-video-vesa-lts-raring xserver-xorg-video-vmware-lts-raring
The following NEW packages will be installed:
libgl1-mesa-glx libgl1-mesa-glx:i386 libglapi-mesa libglapi-mesa:i386
xserver-xorg xserver-xorg-core xserver-xorg-input-evdev
0 upgraded, 7 newly installed, 41 to remove and 0 not upgraded.
Need to get 2,295 kB of archives.
After this operation, 37.8 MB disk space will be freed.
Do you want to continue [Y/n]?

This scares me a lot because it says a lot of stuff will be removed. I experienced this before and it resulted in being left with CLI. Should I run it?