[Samba] Failed to modify entry for user in samba with tdb backend

[Linda W]

Francesc Guasch Ortiz wrote:
>
> When I try to create a new user:
>
>     # smbpasswd -a blabla
>     New SMB password: ****
>     Retype new SMB password: ****
>     Failed to add entry for user blabla.
Very basic thought here, and sorry if you already checked this, but
There are parameters for <samba cfg dir(usually /etc/samba?)/smb.conf
that specify how to do those things.

have you tried running those command manually to see if they
work?
>  man smb.conf |egrep 'script.*\([GS]\)'
       abort shutdown script (G)
       add group script (G)
       add machine script (G)
       add user script (G)
       add user to group script (G)
       check password script (G)
       delete group script (G)
       delete user from group script (G)
       delete user script (G)
       logon script (G)
       magic script (S)
       rename user script (G)
       set primary group script (G)
       shutdown script (G)
       username map script (G)

Many (*some*) have builtin defaults.
So if you don't have them in your smb.conf file, you
might check to see if the defauts work. 
(as root:)
testparm -sv|grep script

(if you don't do it as root it prints nothing which
is a bit weird as I can see the parms using 'more'(or less)
on the file directly.