SymptomsLog in to Plesk Panel, go to Home -> Change Administrator's Password and try to change the password. You will receive the following error:
Unable to change the administrator's password: C Exception: 3221225477 <br> at Unable to set config variable:(zif_set_admin_password line 357)
ResolutionAs a possible workaround, switch Plesk Panel to fastcgi mode with the following command:
reconfigurator.exe --configure-plesk-web-server --php-handler-type=fastcgi --force
This problem has been fixed in Parallels Panel 10.4. Consider upgrade Parallels Panel on your server.