Unable to install or update Plesk: Operation too slow. Less than 500 bytes/sec transferred the last 30 seconds

Symptoms

• Unable to update/install Plesk with one of the errors below:

  CONFIG_TEXT: Error: Failed to download the file http://autoinstall-win.plesk.com/pool/release/PLESK-WIN_18.0.39_7267/dist-windows/plesk-core.zip (203.0.113.2):
  Operation too slow. Less than 500 bytes/sec transferred the last 30 seconds
  Not all packages were installed.
  Please try to install packages again later.
  Please resolve this issue and try to install the packages again.
  Visit https://support.plesk.com/ to search for a solution.

  ---

  CONFIG_TEXT: Error: Failed to download the file http://autoinstall-win.plesk.com/pool/release/PLESK-WIN_18.0.39_7267/dist-windows/plesk-core.zip (203.0.113.2):
  Recv failure: Connection was reset

Cause

Antivirus software is blocking the installation script from downloading certain files from http://autoinstall-win.plesk.com because the antivirus treats it as unsafe.

Resolution

1. Connect to the server via RDP.

2. Disable an antivirus software or add the auto-installer URL http://autoinstall-win.plesk.com to exceptions.

3. Ru-run Plesk installation/update.