failed to open stream: No such file or directory

[Mikado]

Good morning,

I come upgrade 1.3.7.1 to 1.3.8 and and I acquire this message :

Warning: main(includes/languages/french.php) [function.main]: failed to open stream: No such file or directory in /home/users/.../.../www/admin/includes/init_includes/init_languages.php on line 31

Warning: main(includes/languages/french.php) [function.main]: failed to open stream: No such file or directory in /home/users/.../.../www/admin/includes/init_includes/init_languages.php on line 31

Fatal error: main() [function.require]: Failed opening required 'includes/languages/french.php' (include_path='.:/home/temporaire/upload:/usr/local/lib/php/') in /home/users/.../.../www/admin/includes/init_includes/init_languages.php on line 31

What is this?