Error below after trying to do a restore :

ERREUR GÉNÉRÉE PAR L’UTILISATEUR : Erreur MySQLi : SHOW FULL COLUMNS FROM [Préfixe]admintoobject a échoué. MySQLi a renvoyé l’erreur Table 'mytable._admintoobject' doesn't exist dans /home/users3/b/espacet/www/globaux/zp-core/functions-db-MySQLi.php à la ligne 78

trigger_error called from query (functions-db-MySQLi.php [78])

from db_show (functions-db-MySQLi.php [298])

from db_list_fields (functions-db-MySQLi.php [309])

from backup_restore.php [282]

All is working correctly except a restore...

Something is wrong with the tables. The actual table name would be [i]prefix[/i]admin_to_object. The query you show has left out the underscores.
I have no clue as to why the name would be wrong in the backup, but the only side-effect might be that some user "managed objects" would be lost. If you have not used that feature then no harm is done.

I found, i have no prefix for the table, then the table name begin with _ (underscore)

It was the missing underscores WITHIN the table name that was the issue. And anyway, if there is an underscore in front of the table name then underscore is the prefix.

There is the _ in the table name, but the restore does not work in that case.

Ok. there is a fix in the support build for this.

Thanks Stephen, on my test system i don't put the prefix, i thinks that he needs to be mandatory during the installation.