when we try to add a new user, we have to enter a dummy password. although it says it is not mandatory, it doesnt add the user without password. it says "when no password is entered one will be created randomly" but doesnt...

so, say "123456" as password and create user. that password is not used as long as LDAP Active directory is used, and the user exists in LDAP, since the password in LDAP will be used to authonticate the user.