Plesk upgrade fails: The following packages cannot be authenticated!

Symptoms

• In /tmp/autoinstaller3.log, the following error is shown:

  WARNING: The following packages cannot be authenticated!
   mysql-client mysql-server mysql-community-client mysql-common
   mysql-community-server

• Key for MySQL repository is shown as expired:

  # apt-key list
  /etc/apt/trusted.gpg
  ——————–
  …
  pub 1024D/5072E1F5 2003-02-03 [expired: 2017-02-16]
  uid MySQL Release Engineering [email protected]

• The following error is displayed when using apt-get update command:

  Reading package lists... Done
   W: GPG error: http://repo.mysql.com wheezy Release: The following signatures were invalid: KEYEXPIRED 1487236823 KEYEXPIRED 1487236823 KEYEXPIRED 1487236823

Cause

Failed upgrade attempt due to expired MySQL repository key caused by MySQL Bug.

Resolution

1. Connect to the server via SSH.

2. Run the the following commands:

   # apt-key adv –recv-keys –keyserver keys.gnupg.net 5072E1F5
   # apt-get update

   This will update the repository keys for MySQL and check if it is possible to access the MySQL repository.