Fixed !
The problem came for the Language Switcher plugin. I had to install the last version.
http://www.poplarware.com/downloads/language_switcher
Sadly, this plugin is not longer supported.
Thank you for taking the time to answer !
The plug-in seems to run on the last version of WordPress and I don’t think it’s the problem’s source because I still have it if I desactivate the plug-in.
When I try to create a new category, I have a huge error message. The beginning is :
Warning: Cannot modify header information - headers already sent by (output started at /homepages/25/d264243895/htdocs/blog/wp-includes/taxonomy.php:1347) in /homepages/25/d264243895/htdocs/blog/wp-includes/class-wp-ajax-response.php on line 129
I never heard about “taximony” before, is that rules the categories in the last WP versions ?
