I think you did not update to pre-release, thus option is not there.I already use this command before I just forgot to remove "=" .
Now I am getting this:
/usr/local/directadmin# /usr/local/directadmin/directadmin set brute_force_pureftpd_log /var/log/pureftpd.log
Error with the current values:
Cannot find 'brute_force_pureftpd_log' in the directadmin.conf
After update directadmin.conf manually.
brute_force_pureftpd_log=/var/log/pureftpd.log in directadmin.conf but still get the same error with the directadmin set command.