Cannot install extensions from extensions.gnome.org

[shinyblue]

I used to be able to install extensions by clicking the slidy switch, e.g. at
https://extensions.gnome.org/extension/15/alternatetab/

Now when I operate the switch it says ON, but nothing happens. I do not get the darkened confirmation screen. My .xsession-errors file then contains the following error:

    JS ERROR: !!! Exception was: TypeError: info is null
    JS ERROR: !!! lineNumber = '83'
    JS ERROR: !!! fileName = '"/usr/share/gnome-shell/js/ui/extensionSystem.js"'
    JS ERROR: !!! stack = '"([object _private_Soup_SessionAsync],[object _private_Soup_Message])@/usr/share/gnome-shell/js/ui/extensionSystem.js:83
"'
    JS ERROR: !!! message = '"info is null"'

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-shell 3.4.1-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-56.86~lp1255022Commit99a1224-generic 3.2.51
Uname: Linux 3.2.0-56-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
Date: Tue Dec 3 14:51:58 2013
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
SourcePackage: gnome-shell
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 12.04 (precise) reached end-of-life on April 28, 2017.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test.

[Launchpad Janitor (janitor)]

[Expired for gnome-shell (Ubuntu) because there has been no activity for 60 days.]