There are many solutions. If you use AWStats try this
/usr/local/psa/admin/sbin/webstatmng --set-configs --stat-prog=awstats --domain-name=yourdomain.tld
Thereafter
/usr/local/psa/admin/sbin/statistics
Or try to repair Plesk with bootstrapper
/usr/local/psa/bootstrapper/pp12.5-bootstrapper/bootstrapper.sh
PP12.5 is the version. Maybe you need to change to the right version.