/usr/sbin/userdel execution failed is shown while removing additional FTP account

Symptoms

Unable to remove additional FTP account/Web User from Plesk when there are php-fpm processes running on behalf of the system users of the subscription, the following error appears in Plesk:

PLESK_ERROR: Unable to execute usermng: usermng: /usr/sbin/userdel execution failed:
userdel: user ftpadd is currently used by process 5022
usermng: Unable to delete user:

Cause

Bug #PPPM-4225 . It is fixed in Plesk Onyx.

Resolution

Upgrade to the latest Plesk version .

If upgrade is not possible:

1. Go to Home > Domains > example.com > PHP Settings and switch PHP handler to one with CGI/FastCGI support.
2. Go to Home > Domains > example.com > FTP Access/Web USers and remove an account.
3. Set back PHP handler in PHP Settings .

If steps above did not help remove this account directly from Plesk database with below steps:

1. Backup Plesk database.

2. Delete orphaned records:

   # MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -Dpsa -e "select account_id from sys_users where login='ftpadd'"
   +------------+
   | account_id |
   +------------+
   | 11 |
   +------------+
   
   # MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -Dpsa -e "delete from accounts where id=11"
   # MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -Dpsa -e "delete from sys_users where login='ftpadd'"

3. Remove the user from the system:

   # /usr/sbin/userdel ftpadd