Plesk host / Plesk Control Panel / Plesk container is slow or unresponsive. Some services (for example RDP) can be unstable. Also migration of large number of subscriptions may stop with "Failed" status and referrals to psabackup.dll
A lot of session files (like 500,000) are contained in the folder "
Remove all files from the folder "
The following command in
cmd.exe window can be used:
del /f/s/q "%plesk_dir%\admin\sessions" > nul