wp_usermeta: Table ‘hallnet.wp_usermeta’ doesn’t exist

This has been reported a number of times and I’ve not been able to provide much of a solution. Is your host free.fr? See some of these recent threads: http://wordpress.org/tags/wp_usermeta

Might also see if localhost rather than sql.free.fr works for DB_HOST in your wp-config.php.

[edit] I’ve also posted to wp-hackers for assistance with this.