Plesk Installer web interface is stuck in an attempt to install/remove any Plesk component

Symptoms

• Ubuntu 18.04 is used.

• Unable to install/remove any Plesk component via Plesk > Tools & Settings > Updates & Upgrades > Add/Remove components because the operation is stuck on the following step:

  CONFIG_TEXT: All patches were applied

• Refreshing the page gives the next error:

  CONFIG_TEXT: ERR_CONNECTION_TIMED_OUT

• The /var/log/plesk/install/autoinstaller3.log file informs that the installation was completed successfully:

  CONFIG_TEXT: All patches were applied.
  Patches were installed successfully.
  The changes were applied successfully.

Cause

This is Plesk bug #PPPM-10191 which will be fixed in future product updates.

Resolution

As a workaround add/remove components via Command Line Interface (CLI):

1. Connect to the server via SSH.

2. Launch Plesk Installer:

   # plesk installer

   Note: If the command below is completed with the next output:
   
   BUSY: Update operation was locked by another update process
   
   Follow steps from this article.

3. Follow the instructions on the screen and install/remove the required component.

Additional information

• How to install / uninstall Plesk components?

• Unable to open the "Updates and Upgrades" page or start Plesk Installer in CLI: Update operation was locked by another update process