Plesk update fails: bind9 package is half-configured

Symptoms

• Plesk update fails on an Ubuntu server.

• The following error is displayed in the Plesk interface or CLI during the update process:

  CONFIG_TEXT: ERROR: Components and product validation detected at least one important issue: 
  Package manager check 
  The system package manager reports the following problems: 
  The following packages are only half configured, probably due to problems 
  configuring them the first time. 
  The configuration should be retried using 
  dpkg --configure <package> or the configure menu option in dselect: 
  bind9 Internet Domain Name Server

• Running dpkg --configure bind9 manually via SSH shows the following error:

  CONFIG_TEXT: Setting up bind9 (1:9.18.39-0ubuntu0.24.04.1) ... 
  /etc/bind/named.conf.options:2: option 'dnssec-enable' no longer exists 
  dpkg: error processing package bind9 (--configure): 
  installed bind9 package post-installation script subprocess returned error exit status 1

Cause

The bind9 package post-install script fails because of an obsolete dnssec-enable directive present in the /etc/bind/named.conf.options file.

In BIND 9.16 and newer, the dnssec-enable option was completely removed. Because this obsolete directive is present, BIND considers the configuration invalid and refuses to complete its package setup. This directive was likely introduced by a deprecated third-party extension named "DNSSEC Manager" (by Admin-Ahead) that left its configuration behind.

Resolution

1. Connect to the server via SSH.

2. Open the file /etc/bind/named.conf.options using a text editor, for example, nano:

   # nano /etc/bind/named.conf.options

3. Locate the dnssec-enable yes; line and remove it, or comment it out by adding // at the beginning of the line.
4. Save the file and close the editor.

5. Complete the pending package configurations by running the following command:

   # dpkg --configure -a

6. Restart the Plesk update process.

Note: It is strongly recommended to remove the deprecated third-party DNSSEC Manager extension from Plesk to prevent future issues. Log in to Plesk, go to Extensions > My Extensions, locate DNSSEC Manager, and click Remove.