Plesk Installer fails on Debian/Ubuntu: The following packages have unmet dependencies: nginx

Symptoms

• Plesk Installer fails on Debian/Ubuntu-based distributions with:

  CONFIG_TEXT: The following packages have unmet dependencies:
  libnginx-mod-http-geoip : Depends: nginx-common (= 1.14.0-0ubuntu1.2) but it is not going to be installed
  libnginx-mod-http-image-filter : Depends: nginx-common (= 1.14.0-0ubuntu1.2) but it is not going to be installed
  libnginx-mod-http-xslt-filter : Depends: nginx-common (= 1.14.0-0ubuntu1.2) but it is not going to be installed
  libnginx-mod-mail : Depends: nginx-common (= 1.14.0-0ubuntu1.2) but it is not going to be installed
  libnginx-mod-stream : Depends: nginx-common (= 1.14.0-0ubuntu1.2) but it is not going to be installed
  nginx : Depends: nginx-core (< 1.14.0-0ubuntu1.2.1~) but it is not going to be installed or
  nginx-full (< 1.14.0-0ubuntu1.2.1~) but it is not going to be installed or
  nginx-light (< 1.14.0-0ubuntu1.2.1~) but it is not going to be installed or
  nginx-extras (< 1.14.0-0ubuntu1.2.1~) but it is not going to be installed
  Depends: nginx-core (>= 1.14.0-0ubuntu1.2) but it is not going to be installed or
  nginx-full (>= 1.14.0-0ubuntu1.2) but it is not going to be installed or
  nginx-light (>= 1.14.0-0ubuntu1.2) but it is not going to be installed or
  nginx-extras (>= 1.14.0-0ubuntu1.2) but it is not going to be installed

Cause

Dependency conflict between the Plesk 'sw-nginx' package and 3rd-party nginx packages.

Resolution

1. Connect to the Plesk server via SSH.

2. Remove all 3rd-party nginx packages that are mentioned in the error message:

   # dpkg -r package1 package2 package3 ...

   • For example, based on the error message above, the following packages should be removed:

     # dpkg -r libnginx-mod-http-geoip libnginx-mod-http-image-filter libnginx-mod-http-xslt-filter libnginx-mod-mail libnginx-mod-stream nginx nginx-full nginx-extras nginx-core nginx-light nginx-extras

   If the packages fail to be removed using the command above, purge them with the command:

   # dpkg -P --force-depends package1 package2 package3 ...

3. Verify that only the 'sw-nginx' package is installed:

   # dpkg -l | grep nginx
   ii sw-nginx