As I see the problem is in the skelmng execution, so I did try to run the command manually, the ouput is:
[root@]# /usr/local/psa/admin/sbin/skelmng --setup-skel --vhost-name domain.tld --id 0 --www-root=/home/www/vhosts/domain.tld/httpdocs --cgi-bin-path=/home/www/vhosts/domain.tld/cgi-bin
Unexpected error: Directory /home/www/vhosts/domain.tld does not represent a virtual host