Some subdomains are not visible in Plesk Panel after executing the upgrade procedure.
If you try to delete a domain, you see error message like the following:
Missing parameter 'dirname' or previous parameter is empty.
Some subdomains were not correctly upgraded during the Plesk upgrade procedure.
You can find such subdomains with the following SQL query in the PSA database:
# MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -u admin psa -e 'select count(*) from subdomains'
You will see non zero result if part of subdomains was not upgraded.
Run an upgrade of subdomains again with the following command:
# /usr/local/psa/bin/sw-engine-pleskrun "/usr/local/psa/admin/plib/scripts/upgrade_subdomains_1011.php"