Installation of Plesk micro-updates fails: Failed to fetch autoinstall.plesk.com/ubuntu/PSA_17.8.11/.. 404 Not Found

Symptoms

• Plesk upgrade through plesk utility fails with 404 error:

  # plesk installer
  …
  E: Failed to fetch http://autoinstall.plesk.com/ubuntu/PSA_17.8.11/../../PSA_17.8.11/dist-deb-Ubuntu-16.04-x86_64/bootstrapper/sw-engine-cli-2.24_2.24.9-ubuntu.16.04.180409.1642_amd64.deb 404 Not Found
  E: Unable to fetch some archives, maybe run apt-get update or try with –fix-missing?

• Following error during micro-update reinstallation:

  # plesk installer –select-release-current –reinstall-patch –upgrade-installed-components
  E: Version ‘17.8.11-ubuntu16.04.build1708180329.14’ for ‘pp17.8.11-bootstrapper’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180322.11’ for ‘plesk-completion’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180328.17’ for ‘plesk-repair-kit’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180321.15’ for ‘psa-locale-base-en-us’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180326.12’ for ‘psa-updates’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180328.11’ for ‘plesk-l10n’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708180321.20’ for ‘psa-watchdog’ was not found
  E: Version ‘17.8.11-ubuntu16.04.build1708181211.16’ for ‘psa-locale-base-en-us’ was not found
  E: Version ‘4.8.4-ubuntu16.04.build1708181212.18’ for ‘psa-phpmyadmin’ was not found

• The following error can be found in /var/log/plesk/panel.log:

  The repository 'http://repo.zabbix.com/zabbix/4.1/debian stretch Release' does no longer have a Release file.

Cause

Repository misconfiguration in /etc/apt/sources.list.

Resolution

1. Connect to the server via SSH.

2. Rename the original /etc/apt/sources.list file:

   # mv /etc/apt/sources.list{,.orig}

3. Create /etc/apt/sources.list using vi with the following content:

   • Ubuntu 16:

     deb http://archive.ubuntu.com/ubuntu xenial main restricted universe
      deb http://archive.ubuntu.com/ubuntu xenial-updates main restricted universe 
      deb http://security.ubuntu.com/ubuntu xenial-security main restricted universe multiverse 
      deb http://archive.canonical.com/ubuntu xenial partner

   • Debian 9:

     deb http://ftp.debian.org/debian stretch stretch main contrib non-free
      deb http://ftp.debian.org/debian stretch-updates main contrib non-free 
      deb http://security.debian.org/debian-security stretch/updates main contrib non-free