Hello Javi,
I think that the problem is solved.
The reason why i get the samba error on mij operational server was because i have copyed the nerw file " Backup.pm " using a file manager on the server ( i use lxde small desktop to make things easyer ) the old file " Backup.pm " was overwritten at that time and when i restarted eBox samba was not restarted again.
So the only thing to solve the samba problem was, in the eBox admin menu unselect all modules needed for a file and print server. Then in command mode remove ebox office ( sudo apt-get remove ebox-office ). Reboot the server, in command mode reïnstall ebox-office ( sudo apt-get install ebox-ofice ) then select all the needed modules for a file and printserver in the ebox admin application.
The server is ok now , evrything is working again.
Next step, on my operational server downloaded the new module " Backup.pm " and copyed the file in command mode ( cp -bf /tmp/Backup.pm /usr/share/perl5/EBox/backup.pm ), reboot the server, made a backup of the server configuration in the ebox admin interface.
Install a new eBox server from scratch, restore the data on the new server, restore the configuration backup and reboot the new server.Now the new server has all the data and cofiguration from the old server and works fine.
So the new " backup.pm " file has solved the access control list.
Sorry it was my fault, i did not correctly copyed the Backup.pm file
Thanks for the intervention,
Ian