Unable to install Softaculous or SitePad extensions: POSIX extension is not loaded in PHP

Symptoms

• Unable to install Softaculous or SitePad Website Builder extensios:

  PLESK_ERROR: Error: Failed to install the extension:
  Executing /usr/local/psa/tmp/module8JzWud/plib/scripts/pre-install.php failed:
  POSIX extension is not loaded in PHP. Please enable it to continue installation

  Or

  PLESK_ERROR: Error: Failed to install the extension:
  Execution of /usr/local/psa/tmp/module8JzWud/plib/scripts/pre-install.php failed with exit code 1 and the output:
  POSIX extension is not loaded in PHP. Please enable it to continue installation

• The system PHP has no posix extension enabled:

  # php -m | grep posix
  #

Cause

The php-process package that is required for Softaculous Ltd software is not installed on a server.

Resolution

1. Connect to the server via SSH;

2. Install the required package:

   # yum install php-process

3. Verify it is loaded:

   # php -m | grep -i posix
   posix