Unable to upgrade Plesk Onyx to Plesk Obsidian: ailed to solve dependencies: plesk-mail-pc-driver-18.0-2.centos.7+p18.0.18.1+t190909.1738.x86_64 requires postfix >= 2:3.4.5

Symptoms

• Unable to upgrade Plesk Onyx for Plesk Obsidian with the following error:

  CONFIG_TEXT: packages excluded due to repository priority protections
  Package 2:postfix-2.10.1-7.el7.x86_64 already installed and latest version
  Package 2:postfix-2.10.1-7.el7.x86_64 already installed and latest version
  Package 2:postfix-2.10.1-7.el7.x86_64 already installed and latest version
  Attempt to remove 'psa-phpfpm-configurator' to resolve conflict has succeeded
  Attempt to remove 'plesk-ext-catalog' to resolve conflict has succeeded
  Attempt to remove 'psa-pylibplesk' to resolve conflict has succeeded
  Attempt to remove 'plesk-base' to resolve conflict has succeeded
  Attempt to remove 'plesk-skins' to resolve conflict has succeeded
  Attempt to remove 'plesk-ext-rest-api' to resolve conflict has succeeded
  Exception: Failed to solve dependencies:
  plesk-mail-pc-driver-18.0-2.centos.7+p18.0.18.1+t190909.1738.x86_64 requires postfix >= 2:3.4.5
  
  ERROR: The Yum utility failed to install the required packages.
  Attention! Your software might be inoperable.
  Visit https://support.plesk.com/ to search for a solution.
  exit status 1

• Yum plugins are installed and enabled in /etc/yum/pluginconf.d/:

  # ls /etc/yum/pluginconf.d/
  protectbase.conf priorities.conf

  # cat /etc/yum/pluginconf.d/priorities.conf
  [main]
  enabled = 1

Cause

Plesk bug with ID #PPPM-11026 which will be fixed in future Plesk updates.

Resolution

Apply one of the following workarounds:

1. Connect to the server via SSH.

2. Disable plugins in /etc/yum/pluginconf.d/, for example:

   # cat /etc/yum/pluginconf.d/priorities.conf
   [main]
   enabled = 0

3. Proceed with Plesk upgrade:

   # /usr/local/psa/admin/bin/autoinstaller