gnome shell extension

[Patrick Dupre]

Hello,

With fedora 21, I get 
We cannot detect a running copy of GNOME on this system, so some parts of the interface may be disabled. See our troubleshooting entry for more information.

when I try to install some gnome extensions (https://extensions.gnome.org/)

What is missing?
I installed gnome-tweak-tool


Thank for your help.

===========================================================================
 Patrick DUPRÉ                                 | | email: pdupre at gmx.com
 Laboratoire de Physico-Chimie de l'Atmosphère | |
 Université du Littoral-Côte d'Opale           | |
 Tel.  (33)-(0)3 28 23 76 12                   | | Fax: 03 28 65 82 44
 189A, avenue Maurice Schumann                 | | 59140 Dunkerque, France
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