hi!
I have Ubuntu 12.04.3.
I don t know what i changed but now when i cant open gedit editor.
when i type
stagiaire@u64:~$ gedit
(process:2629): Gtk-WARNING **: Locale not supported by C library.
Using the fallback 'C' locale.
what's wrong?what i have to do?

These lines just indicate the the locale gedit was trying to use aren't supported by your C library.

(process:2629): Gtk-WARNING **: Locale not supported by C library.

Using the fallback 'C' locale.

gedit should have continued to start up. Did it? If so, can you use it?

You said you had no idea what you had done. Welcome to the world of 'I did something maybe' but I've no way of remembering <GRIN> Happens to me alot. When I encounter situations like this I try to remember what I was playing around with. If you can remember even partially what you were doing, someone might see what the problem is. By the way, I am assuming gedit wasn't giving these warnings before hand.

Coordially,

It's a good idea to keep a diary of all the tweaks, updates and installations. So if something goes wrong I can refer back to any changes. My "changelog" is just a simple text file but it helped me a lot with back tracking (tracing). Good luck.

I just tried to open a .python file with gedit and after that I had the problem..

Well, I don't see what that could cause. You might try Ubuntu forum here on LQ.

dpkg-reconfigure locales

Would that work?