Plesk Updates page is not working: 504 Gateway Time-out

Symptoms

• The Plesk Updates page returns a 504 error

• These entries are logged to /var/log/plesk/install/autoinstaller3.log:

  Failed to detach from parents cgroup, installer might be unexpectedly killed later by the system
  DEBUG: web server PID: 111111
  Error: Can't start build-in web-server
  Not all packages were installed.
  Please try to install packages again later.
  Please resolve this issue and try to install the packages again.

• There is a stuck installer process:

  # ps aux | grep [i]nstaller
  root 111111 0.0 0.0 12345 1234 ? S Jan01 0:00 /var/cache/parallels_installer/parallels_installer_Debian_11.0_x86_64_3.63.0 --service-mode --enable-xml-output --with-ssl --ssl-cert /opt/psa/admin/conf/httpsd.pem --branch release,stable --web-interface --disable-browser

Cause

The updates page is timing out because the stuck process doesn't let a new installer session start.

Resolution

Kill the stuck process to let Plesk installer start normally again.

1. Log in over SSH

2. Get the installer's process ID:

   # ps aux | grep [i]nstaller
   root 111111 0.0 0.0 12345 1234 ? S Jan01 0:00 /var/cache/parallels_installer/parallels_installer_Debian_11.0_x86_64_3.63.0 --service-mode --enable-xml-output --with-ssl --ssl-cert /opt/psa/admin/conf/httpsd.pem --branch release,stable --web-interface --disable-browser

3. Use the process ID from the previous step to terminate the stuck process:

   # kill -9 111111

4. Open the Updates page normally