When clicking on Updates and Upgrades in Plesk, the page prompts for a root password or does not open at all with one of the following error messages in a web-browser:
The connection has timed out
This site can’t be reached
When starting Plesk Installer in a command-line interface, the following message is shown:
BUSY: Update operation was locked by another update process.
Error: Unable to start Plesk Installer. The following error has occurred: Installation could not be started: another installation procedure is currently running.
A Plesk Installer process is running on the server already, but only one Plesk Installer process can be launched at a time.
Terminate active Plesk Installer processes:
Note: Before applying the solution below, make sure that other users on the Plesk server are not using Plesk Installer.
Stop Plesk Installer processes (on Windows Server, use a command prompt as Administrator):
# plesk installer stop
For Plesk Onyx, apply the following steps:
For Plesk on Linux
Connect to the Plesk server via SSH
Find the PIDs of Plesk Installer processes:
# ps aux | grep install | grep -v grep
root 12345 1.5 0.8 136856 18280 ? S 20:43 0:00 /var/cache/parallels_installer/parallels_installer_CentOS_7_x86_64_3.21.3 –service-mode –enable-xml-output –ssl-cert /usr/local/psa/admin/conf/httpsd.pem –branch release,stable –web-interface –with-ssl –disable-browser
root 12346 0.0 0.1 109776 2808 ? S 20:43 0:00 /var/cache/parallels_installer/parallels_installer_CentOS_7_x86_64_3.21.3 –service-mode –enable-xml-output –ssl-cert /usr/local/psa/admin/conf/httpsd.pem –branch release,stable –web-interface –with-ssl –disable-browser
Kill found processes using the command below. Replace 12345 12346 with actual PIDs from the step above:
# kill -9 12345 12346
/tmp/psa-installer.lockfile, if it exists
Start Plesk Installer
For Plesk on Windows Server
Apply one of the following solutions:
Terminate Plesk Installer processes using a command prompt:
Connect to the Plesk server via RDP
Start a command prompt
Find the PID of a Plesk Installer process:
wmic process where “caption like ‘%installer%'” get processId,caption
**Caption ProcessIdai.exe 6444
Kill the process using its PID:
taskkill /PID 6444 /F
taskkill /FI “IMAGENAME eq ai.exe” /F
Terminate Plesk Installer processes using Windows Task Manager
Open Task Manager (Open Windows Start > type “Task Manager”)
Right-click on each existing “Plesk Installer” process and click End Task:
Note: Plesk Installer processes can have one of the following names depending on Plesk version: Plesk Installer, ai.exe, parallels-installer.exe or plesk-installer.exe.